Objective Our previous study showed that tumor tissue-derived formaldehyde at low concentrations plays an important role in bone cancer pain through activating transient receptor potential vanilloid subfamily member 1...Objective Our previous study showed that tumor tissue-derived formaldehyde at low concentrations plays an important role in bone cancer pain through activating transient receptor potential vanilloid subfamily member 1 （TRPV 1）. The present study further explored whether this tumor tissue-derived endogenous formaldehyde regulates TRPV1 expres- sion in a rat model of bone cancer pain, and if so, what the possible signal pathways are during the development of this type of pain. Methods A rat model of bone cancer pain was established by injecting living MRMT-1 tumor cells into the tibia. The formaldehyde levels were determined by high performance liquid chromatography, and the expression of TRPV1 was examined with Western blot and RT-PCR. In primary cultured dorsal root ganglion （DRG） neurons, the ex- pression of TRPV1 was assessed after treatment with 100 ~tmol/L formaldehyde with or without pre-addition of PD98059 [an inhibitor for extracellular signal-regulated kinase], SB203580 （a p38 inhibitor）, SP600125 [an inhibitor for c-Jun N- terminal kinase], BIM [a protein kinase C （PKC） inhibitor] or LY294002 [a phosphatidylinositol 3-kinase （PI3K） inhibi- tor]. Results In the rat model of bone cancer pain, formaldehyde concentration increased in blood plasma, bone marrow and the spinal cord. TRPV1 protein expression was also increased in the DRG. In primary cultured DRG neurons, 100 p^mol/L formaldehyde significantly increased the TRPV1 expression level. Pre-incubation with PD98059, SB203580, SP600125 or LY294002, but not BIM, inhibited the formaldehyde-induced increase of TRPV1 expression. Conclusion Formaldehyde at a very low concentration up-regulates TRPV1 expression through mitogen-activated protein kinase and PI3K, but not PKC, signaling pathways. These results further support our previous finding that TRPV1 in peripheral after- ents plays a role in bone cancer pain.展开更多
The pain-relieving effect of acupuncture is known to involve primary afferent nerves(PANs) via their roles in signal transmission to the CNS.Using single-unit recording in rats,we characterized the generation and tran...The pain-relieving effect of acupuncture is known to involve primary afferent nerves(PANs) via their roles in signal transmission to the CNS.Using single-unit recording in rats,we characterized the generation and transmission of electrical signals in Aβ and Aδ fibers induced by acupuncture-like stimuli.Acupuncture-like signals were elicited in PANs using three techniques:manual acupuncture(MAc),emulated acupuncture(EAc),and electro-acupuncture(EA)-like peripheral electrical stimulation(PES).The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz,respectively.The frequency of discharges in PANs was correlated with the frequency of PES.The highest discharge frequency was 246 Hz in Aβ fibers and 180 Hz in Aδ fibers.Therefore,EA in a dense-disperse mode(at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc.Frequencies of EA output>250 Hz appear to be obsolete for pain relief.展开更多
Neurosteroids are synthesized in the nervous system from cholesterol or steroidal precursors imported from peripheral sources. These compounds are important allosteric modulators of γ-aminobutyric acid A receptors （...Neurosteroids are synthesized in the nervous system from cholesterol or steroidal precursors imported from peripheral sources. These compounds are important allosteric modulators of γ-aminobutyric acid A receptors （GABAARs）, which play a vital role in pain modulation in the lateral thalamus, a main gate where somatosensory information enters the cerebral cortex. Using high-perfor mance liquid chromatography/tandem mass spectrometry, we found increased levels of neurosteroids （pregnenolone, progesterone, deoxycorticosterone, allopregnanolone, and tetrahydrodeoxycorticosterone） in the chronic stage of neuropathic pain （28 days after spared nerve injury） in rats.The expression of the translocator protein TSPO, the upstream steroidogenesis rate-limiting enzyme, increased at the same time. In vivo stereotaxic microinjection of neurosteroids or the TSPO activator AC-5216 into the lateral thalamus （AP -3.0 mm, ML 4-3.0 mm, DV 6.0 mm） alleviated the mechanical allodynia in neuropathic pain, while the TSPO inhibitor PK 11195 exacerbated it. The analgesic effects of AC-5216 and neurosteroids were sig- nificantly attenuated by the GABAAR antagonist bicuculline. These results suggested that elevated neurosteroids in the lateral thalamus play a protective role in the chronic stage of neuropathic pain.展开更多
Cognition and pain share common neural substrates and interact reciprocally: chronic pain compromises cognitive performance, whereas cognitive processes modulate pain perception. In the present study, we established a...Cognition and pain share common neural substrates and interact reciprocally: chronic pain compromises cognitive performance, whereas cognitive processes modulate pain perception. In the present study, we established a non-drug-dependent rat model of context-based analgesia,where two different contexts(dark and bright) were matched with a high(52°C) or low(48°C) temperature in the hot-plate test during training. Before and after training,we set the temperature to the high level in both contexts.Rats showed longer paw licking latencies in trials with the context originally matched to a low temperature than those to a high temperature, indicating successful establishment of a context-based analgesic effect in rats. This effect was blocked by intraperitoneal injection of naloxone(an opioid receptor antagonist) before the probe. The context-based analgesic effect also disappeared after optogenetic activation or inhibition of the bilateral infralimbic or prelimbic sub-region of the prefrontal cortex. In brief, we established a context-based, non-drug dependent, placebo-like analgesia model in the rat. This model provides a new and useful tool for investigating the cognitive modulation of pain.展开更多
Objective Formaldehyde at high concentrations is a contributor to air pollution. It is also an endogenous metabolic product in cells, and when beyond physiological concentrations, has pathological effects on neurons. ...Objective Formaldehyde at high concentrations is a contributor to air pollution. It is also an endogenous metabolic product in cells, and when beyond physiological concentrations, has pathological effects on neurons. Formaldehyde induces mis-folding and aggregation of neuronal tau protein, hippocampal neuronal apoptosis, cognitive impairment and loss of memory functions, as well as excitation of peripheral nociceptive neurons in cancer pain models. Intracellular calcium （[Ca2＋]i） is an important intracellular messenger, and plays a key role in many pathological processes. The present study aimed to investigate the effect of formaldehyde on [Ca2＋]i and the possible involvement of N-methyl-D-aspartate receptors （NMDARs） and T-type Ca2＋ channels on the cell membrane. Methods Using primary cultured hippocampal neurons as a model, changes of [Ca2＋]i in the presence of formaldehyde at a low concentration were detected by confocal laser scanning microscopy. Results Formaldehyde at 1 mmol/L approximately doubled [Ca2＋]i. （2R）-amino-5-phosphonopentanoate （AP5, 25 μmol/L, an NMDAR antagonist） and mibefradil （MIB, 1 μmol/L, a T-type Ca2＋ channel blocker）, given 5 min after formaldehyde perfusion, each partly inhibited the formaldehyde-induced increase of [Ca：＋]i, and this inhibitory effect was reinforced by combined application of AP5 and MIB. When applied 3 min before formaldehyde perfusion, AP5 （even at 50μmol/L） did not inhibit the formaldehyde-induced increase of [Ca2＋]i, but MIB （1 μmol/L） significantly inhibited this increase by 70%. Conclusion These results suggest that formaldehyde at a low concentration increases [Ca2＋]i in cultured hippocampal neurons; NMDARs and T-type Ca2＋ channels may be involved in this process.展开更多
AIM： To investigate the clinicopathological features of gastrointestinal stromal tumor （GIST） and to study the reference indexes for malignancy. METHODS： Fifty-two cases of primary GIST were distinguished from a g...AIM： To investigate the clinicopathological features of gastrointestinal stromal tumor （GIST） and to study the reference indexes for malignancy. METHODS： Fifty-two cases of primary GIST were distinguished from a group of gastrointestinal mesenchymal tumors using a panel of antibodies such as CD117 and CD34 by immunohistochemical SP method. Their biological behaviors were analyzed using the expression of p21WAF1 and Bax in 52 cases of GIST. RESULTS： Grossly, the tumor size was between 1.5 cm and 13 cm （mean： 5.5 cm）. Focal areas of hemorrhage, necrosis, or small cyst formation could be seen. Microscopically, the tumor was composed of spindle cells （20 cases）, epithelioid cells （20 cases） and mixed cells （12 cases）. Immunohistochemically, CDl17 and CD34 showed diffuse strong positive expressions, the positive rates were 98.1% and 92.3%. SMA, S-100, NSE, NF and MBP showed focal positive expressions, the positive rates were 48.1%, 28.8%, 25%, 21.2% and 42.3% respectively. Vimentins were all positive desmin and CgA were all negative. In normal adult stomach and intestine, the immunoreactive staining for CD117 and CD34 showed immunoreactive interstitial cells of Cajal in myenteric neuroplexus. Among the 52 cases of GIST, 27 were positive for p21WAF1 （51.9%）, 29 for Bax （55.8%）. The expression of p21WAF1 and Bax had no significent difference with the localization, size, histological subtype of GIST, but had a significent difference with the histological grade （P = 0.000, respectively）, p21WAF1 expression had a positive correlation to Bax expression （r = 0.461, P = 0.001, k = 0.459）. CONCLUSION： GIST has complicated arrangements and various cell types. Positivity of CD117 and CD34 is the most valuable factor in diagnosing GIST. Expression of p21WAF1 and Bax plays an important role in potential malignancy and malignancy rather than in benign GIST. p21WAF1 and Bax may be used as the markers in the assessment of GIST malignant potential.展开更多
As a main structure of the limbic system,the hippocampus plays a critical role in pain perception and chronicity.The ventral hippocampal CA1(vCA1)is closely associated with negative emotions such as anxiety,stress,and...As a main structure of the limbic system,the hippocampus plays a critical role in pain perception and chronicity.The ventral hippocampal CA1(vCA1)is closely associated with negative emotions such as anxiety,stress,and fear,yet how vCA1 neurons encode nociceptive information remains unclear.Using in vivo electrophysiological recording,we characterized vCA1 pyramidal neuron subpopulations that exhibited inhibitory or excitatory responses to plantar stimuli and were implicated in encoding stimuli modalities in naïve rats.Functional heterogeneity of the vCA1 pyramidal neurons was further identified in neuropathic pain conditions:the proportion and magnitude of the inhibitory response neurons paralleled mechanical allodynia and contributed to the confounded encoding of innocuous and noxious stimuli,whereas the excitatory response neurons were still instrumental in the discrimination of stimulus properties.Increased theta power and theta-spike coupling in vCA1 correlated with nociceptive behaviors.Optogenetic inhibition of vCA1 pyramidal neurons induced mechanical allodynia in naïve rats,whereas chemogenetic reversal of the overall suppressed vCA1 activity had analgesic effects in rats with neuropathic pain.These results provide direct evidence for the representations of nociceptive information in vCA1.展开更多
CB[n]（n= 6-8） is a family of synthetic macrocyclic host molecules composed of n glycoluril units,which can be employed as molecular reactor.N-Phenyloxypropyl-N＇-ethyl-4,4＇-bipyridium（1） was designed to form a ho...CB[n]（n= 6-8） is a family of synthetic macrocyclic host molecules composed of n glycoluril units,which can be employed as molecular reactor.N-Phenyloxypropyl-N＇-ethyl-4,4＇-bipyridium（1） was designed to form a host-vip inclusion complex with CB[n]（n = 6-8）,subsequently,the bromination reaction of 1 and its corresponding inclusion complexes was investigated in this work.In the case of 1/CB[8],the folded including mode is quite helpful to acquire 1-bormination product completely through intramolecular charge transfer（ICT）,and CB[8]can provide a safe bromination environment for 1.展开更多
It is essential to screen novel luminophores and co-reactants for the development of electrochemiluminescence(ECL)systems.In this work,a series of 1,8-naphthalimide-modified graphitic carbon nitride(CN/1,8-NDI_(x))ECL...It is essential to screen novel luminophores and co-reactants for the development of electrochemiluminescence(ECL)systems.In this work,a series of 1,8-naphthalimide-modified graphitic carbon nitride(CN/1,8-NDI_(x))ECL luminophores were successfully developed for the quantitative determination of Cu^(2+)with K_(2)S_(2)O_(8)as a co-reactant.When CN/1,8-NDI_(x)was immobilized on the surface of the glassy carbon electrode(GCE),a strong ECL signal could be produced(at a potential of-1.3 V vs.Ag/AgCl),which was threefold stronger than that of unmodified g-C_(3)N_(4).The intensity of ECL could be linearly quenched by Cu^(2+)over a concentration range from 5×10^(-9)to 1×10^(-4)mol/L,and with a low limit of detection(LOD)of0.86 nmol/L.Our results may provide a new perspective on the novel ECL platforms development.展开更多
基金supported by grants from the National Natural Science Foundation of China (81070893, 81171042 and 31171063)Beijing Municipal Commission of Education "Grants for Outstanding Ph.D. Program Tutors"+2 种基金the "111" Project of the Ministry of Education of ChinaThe Ministry of Education(BMU20100014)the China Postdoctoral Science Foundation (20090450266)
文摘Objective Our previous study showed that tumor tissue-derived formaldehyde at low concentrations plays an important role in bone cancer pain through activating transient receptor potential vanilloid subfamily member 1 （TRPV 1）. The present study further explored whether this tumor tissue-derived endogenous formaldehyde regulates TRPV1 expres- sion in a rat model of bone cancer pain, and if so, what the possible signal pathways are during the development of this type of pain. Methods A rat model of bone cancer pain was established by injecting living MRMT-1 tumor cells into the tibia. The formaldehyde levels were determined by high performance liquid chromatography, and the expression of TRPV1 was examined with Western blot and RT-PCR. In primary cultured dorsal root ganglion （DRG） neurons, the ex- pression of TRPV1 was assessed after treatment with 100 ~tmol/L formaldehyde with or without pre-addition of PD98059 [an inhibitor for extracellular signal-regulated kinase], SB203580 （a p38 inhibitor）, SP600125 [an inhibitor for c-Jun N- terminal kinase], BIM [a protein kinase C （PKC） inhibitor] or LY294002 [a phosphatidylinositol 3-kinase （PI3K） inhibi- tor]. Results In the rat model of bone cancer pain, formaldehyde concentration increased in blood plasma, bone marrow and the spinal cord. TRPV1 protein expression was also increased in the DRG. In primary cultured DRG neurons, 100 p^mol/L formaldehyde significantly increased the TRPV1 expression level. Pre-incubation with PD98059, SB203580, SP600125 or LY294002, but not BIM, inhibited the formaldehyde-induced increase of TRPV1 expression. Conclusion Formaldehyde at a very low concentration up-regulates TRPV1 expression through mitogen-activated protein kinase and PI3K, but not PKC, signaling pathways. These results further support our previous finding that TRPV1 in peripheral after- ents plays a role in bone cancer pain.
基金supported by the National Key Research and Development Program of the Ministry of Science and Technology,China (2016YFC0105501,2019YFC1712104 and 2016YFF0202802)the National Natural Science Foundation of China (81974169, 81671085 and 61527815)。
文摘The pain-relieving effect of acupuncture is known to involve primary afferent nerves(PANs) via their roles in signal transmission to the CNS.Using single-unit recording in rats,we characterized the generation and transmission of electrical signals in Aβ and Aδ fibers induced by acupuncture-like stimuli.Acupuncture-like signals were elicited in PANs using three techniques:manual acupuncture(MAc),emulated acupuncture(EAc),and electro-acupuncture(EA)-like peripheral electrical stimulation(PES).The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz,respectively.The frequency of discharges in PANs was correlated with the frequency of PES.The highest discharge frequency was 246 Hz in Aβ fibers and 180 Hz in Aδ fibers.Therefore,EA in a dense-disperse mode(at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc.Frequencies of EA output>250 Hz appear to be obsolete for pain relief.
基金supported by grants from the National Basic Research Development Program of China(2013CB531905,2014CB548200,and 2015CB554503)the National Natural Science Foundation of China(81230023,81221002,31200835,81571067,and 21305005)+1 种基金a Key Project of the Ministry of Education of China(109003)the ‘‘111’’ Project of the Ministry of Education of China(B07001)
文摘Neurosteroids are synthesized in the nervous system from cholesterol or steroidal precursors imported from peripheral sources. These compounds are important allosteric modulators of γ-aminobutyric acid A receptors （GABAARs）, which play a vital role in pain modulation in the lateral thalamus, a main gate where somatosensory information enters the cerebral cortex. Using high-perfor mance liquid chromatography/tandem mass spectrometry, we found increased levels of neurosteroids （pregnenolone, progesterone, deoxycorticosterone, allopregnanolone, and tetrahydrodeoxycorticosterone） in the chronic stage of neuropathic pain （28 days after spared nerve injury） in rats.The expression of the translocator protein TSPO, the upstream steroidogenesis rate-limiting enzyme, increased at the same time. In vivo stereotaxic microinjection of neurosteroids or the TSPO activator AC-5216 into the lateral thalamus （AP -3.0 mm, ML 4-3.0 mm, DV 6.0 mm） alleviated the mechanical allodynia in neuropathic pain, while the TSPO inhibitor PK 11195 exacerbated it. The analgesic effects of AC-5216 and neurosteroids were sig- nificantly attenuated by the GABAAR antagonist bicuculline. These results suggested that elevated neurosteroids in the lateral thalamus play a protective role in the chronic stage of neuropathic pain.
基金supported by grants from the National Natural Science Foundation of China (91732107, 31200835, 81571067, and 81521063)the National Basic Research Development Program (973 Program) of China (2014CB548200 and 2015CB554503)
文摘Cognition and pain share common neural substrates and interact reciprocally: chronic pain compromises cognitive performance, whereas cognitive processes modulate pain perception. In the present study, we established a non-drug-dependent rat model of context-based analgesia,where two different contexts(dark and bright) were matched with a high(52°C) or low(48°C) temperature in the hot-plate test during training. Before and after training,we set the temperature to the high level in both contexts.Rats showed longer paw licking latencies in trials with the context originally matched to a low temperature than those to a high temperature, indicating successful establishment of a context-based analgesic effect in rats. This effect was blocked by intraperitoneal injection of naloxone(an opioid receptor antagonist) before the probe. The context-based analgesic effect also disappeared after optogenetic activation or inhibition of the bilateral infralimbic or prelimbic sub-region of the prefrontal cortex. In brief, we established a context-based, non-drug dependent, placebo-like analgesia model in the rat. This model provides a new and useful tool for investigating the cognitive modulation of pain.
基金supported by grants from the National Natural Science Foundation of China (81171042,81070893 and 81221002)the Beijing Outstanding Ph.D.Program Mentor Grantthe Specialized Research Fund for Doctoral Programs of Higher Education, China(20110001110058)
文摘Objective Formaldehyde at high concentrations is a contributor to air pollution. It is also an endogenous metabolic product in cells, and when beyond physiological concentrations, has pathological effects on neurons. Formaldehyde induces mis-folding and aggregation of neuronal tau protein, hippocampal neuronal apoptosis, cognitive impairment and loss of memory functions, as well as excitation of peripheral nociceptive neurons in cancer pain models. Intracellular calcium （[Ca2＋]i） is an important intracellular messenger, and plays a key role in many pathological processes. The present study aimed to investigate the effect of formaldehyde on [Ca2＋]i and the possible involvement of N-methyl-D-aspartate receptors （NMDARs） and T-type Ca2＋ channels on the cell membrane. Methods Using primary cultured hippocampal neurons as a model, changes of [Ca2＋]i in the presence of formaldehyde at a low concentration were detected by confocal laser scanning microscopy. Results Formaldehyde at 1 mmol/L approximately doubled [Ca2＋]i. （2R）-amino-5-phosphonopentanoate （AP5, 25 μmol/L, an NMDAR antagonist） and mibefradil （MIB, 1 μmol/L, a T-type Ca2＋ channel blocker）, given 5 min after formaldehyde perfusion, each partly inhibited the formaldehyde-induced increase of [Ca：＋]i, and this inhibitory effect was reinforced by combined application of AP5 and MIB. When applied 3 min before formaldehyde perfusion, AP5 （even at 50μmol/L） did not inhibit the formaldehyde-induced increase of [Ca2＋]i, but MIB （1 μmol/L） significantly inhibited this increase by 70%. Conclusion These results suggest that formaldehyde at a low concentration increases [Ca2＋]i in cultured hippocampal neurons; NMDARs and T-type Ca2＋ channels may be involved in this process.
文摘AIM： To investigate the clinicopathological features of gastrointestinal stromal tumor （GIST） and to study the reference indexes for malignancy. METHODS： Fifty-two cases of primary GIST were distinguished from a group of gastrointestinal mesenchymal tumors using a panel of antibodies such as CD117 and CD34 by immunohistochemical SP method. Their biological behaviors were analyzed using the expression of p21WAF1 and Bax in 52 cases of GIST. RESULTS： Grossly, the tumor size was between 1.5 cm and 13 cm （mean： 5.5 cm）. Focal areas of hemorrhage, necrosis, or small cyst formation could be seen. Microscopically, the tumor was composed of spindle cells （20 cases）, epithelioid cells （20 cases） and mixed cells （12 cases）. Immunohistochemically, CDl17 and CD34 showed diffuse strong positive expressions, the positive rates were 98.1% and 92.3%. SMA, S-100, NSE, NF and MBP showed focal positive expressions, the positive rates were 48.1%, 28.8%, 25%, 21.2% and 42.3% respectively. Vimentins were all positive desmin and CgA were all negative. In normal adult stomach and intestine, the immunoreactive staining for CD117 and CD34 showed immunoreactive interstitial cells of Cajal in myenteric neuroplexus. Among the 52 cases of GIST, 27 were positive for p21WAF1 （51.9%）, 29 for Bax （55.8%）. The expression of p21WAF1 and Bax had no significent difference with the localization, size, histological subtype of GIST, but had a significent difference with the histological grade （P = 0.000, respectively）, p21WAF1 expression had a positive correlation to Bax expression （r = 0.461, P = 0.001, k = 0.459）. CONCLUSION： GIST has complicated arrangements and various cell types. Positivity of CD117 and CD34 is the most valuable factor in diagnosing GIST. Expression of p21WAF1 and Bax plays an important role in potential malignancy and malignancy rather than in benign GIST. p21WAF1 and Bax may be used as the markers in the assessment of GIST malignant potential.
基金supported by the National Natural Science Foundation of China(81974166,32271053,and 31872774).
文摘As a main structure of the limbic system,the hippocampus plays a critical role in pain perception and chronicity.The ventral hippocampal CA1(vCA1)is closely associated with negative emotions such as anxiety,stress,and fear,yet how vCA1 neurons encode nociceptive information remains unclear.Using in vivo electrophysiological recording,we characterized vCA1 pyramidal neuron subpopulations that exhibited inhibitory or excitatory responses to plantar stimuli and were implicated in encoding stimuli modalities in naïve rats.Functional heterogeneity of the vCA1 pyramidal neurons was further identified in neuropathic pain conditions:the proportion and magnitude of the inhibitory response neurons paralleled mechanical allodynia and contributed to the confounded encoding of innocuous and noxious stimuli,whereas the excitatory response neurons were still instrumental in the discrimination of stimulus properties.Increased theta power and theta-spike coupling in vCA1 correlated with nociceptive behaviors.Optogenetic inhibition of vCA1 pyramidal neurons induced mechanical allodynia in naïve rats,whereas chemogenetic reversal of the overall suppressed vCA1 activity had analgesic effects in rats with neuropathic pain.These results provide direct evidence for the representations of nociceptive information in vCA1.
基金financially supported by State Key Laboratory of Fine Chemicals, Dalian University of Technology, National Natural Science Foundation of China (Nos. 21272030, 21472016, 21306019, 21576042)
文摘CB[n]（n= 6-8） is a family of synthetic macrocyclic host molecules composed of n glycoluril units,which can be employed as molecular reactor.N-Phenyloxypropyl-N＇-ethyl-4,4＇-bipyridium（1） was designed to form a host-vip inclusion complex with CB[n]（n = 6-8）,subsequently,the bromination reaction of 1 and its corresponding inclusion complexes was investigated in this work.In the case of 1/CB[8],the folded including mode is quite helpful to acquire 1-bormination product completely through intramolecular charge transfer（ICT）,and CB[8]can provide a safe bromination environment for 1.
基金financially supported by the National Natural Science Foundation of China(22172011,22078049)
文摘It is essential to screen novel luminophores and co-reactants for the development of electrochemiluminescence(ECL)systems.In this work,a series of 1,8-naphthalimide-modified graphitic carbon nitride(CN/1,8-NDI_(x))ECL luminophores were successfully developed for the quantitative determination of Cu^(2+)with K_(2)S_(2)O_(8)as a co-reactant.When CN/1,8-NDI_(x)was immobilized on the surface of the glassy carbon electrode(GCE),a strong ECL signal could be produced(at a potential of-1.3 V vs.Ag/AgCl),which was threefold stronger than that of unmodified g-C_(3)N_(4).The intensity of ECL could be linearly quenched by Cu^(2+)over a concentration range from 5×10^(-9)to 1×10^(-4)mol/L,and with a low limit of detection(LOD)of0.86 nmol/L.Our results may provide a new perspective on the novel ECL platforms development.
