In this research,a hydroxyl group functionalized metal-organic framework(MOF),UiO-66-(OH)_(2),was synthesized as a "on-off-on" fluore scent switching nanoprobe for highly sensitive and selective detection of...In this research,a hydroxyl group functionalized metal-organic framework(MOF),UiO-66-(OH)_(2),was synthesized as a "on-off-on" fluore scent switching nanoprobe for highly sensitive and selective detection of Fe^(3+),ascorbic acid(AA) and acid phosphatase(ACP).UiO-66-(OH)_(2) emits yellow-green light under ultraviolet light,when Fe^(3+) was added,Fe^(3+) was chelated with hydroxyl group,the electrons in the excited state S_1 of the MOF transferred to the half-filled 3 d orbits of Fe^(3+),resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation.AA could reduce Fe^(3+) to Fe^(2+),which can destroy the electron transfer between UiO-66-(OH)_(2) and Fe^(3+) after AA adding,resulted in nonoccurrence of the nonradiative electron transfer,leading to the recovery of UiO-66-(OH)_(2) fluorescence intensity.The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-L-ascorbic acid(AAP) to produce AA.Benefitting from the hydroxyl group and the characteristics of UiO-66,including the high porosity and large surface area,the developed UiO-66-(OH)_(2) showed extensive advantages as a fluorescent probe for detection of multi-component,such as high sensitivity and selectivity,colorimetric detection,fast response kinetics and easy to operate,economical and secure.This is the first time to use active group functionalized MOFs as a multicomponent sensor for these three substances detection.展开更多
Development of sensitive and accurate methods for sialic acid(SA) determination is of great significance in early cancer diagnosis.Here,a colorimetric-assisted Photoelectrochemical(PEC) sensor was constructed for SA d...Development of sensitive and accurate methods for sialic acid(SA) determination is of great significance in early cancer diagnosis.Here,a colorimetric-assisted Photoelectrochemical(PEC) sensor was constructed for SA detection based on the two pairs of cis-diol groups in SA molecule.With the specific recognition of SA via the two pairs of cis-diol groups,the prepared gold-modified Bi_(2)S_(3)(AuNPs@Bi_(2)S_(3)) and metal organic framework(Au@PCN-224) were introduced to the electrode and formed a sandwich structure.Based on the properties of inert electroconductivity and nanozyme of the PCN-224,dual-readout of photocurrent and visualization was achieved with the presence of 3',3',5',5'-tetramethylbenzidine(TMB).Moreover,to intensify the visualization signal,Ce^(3+) was employed as the mediator to boost the catalysis capability by transferring energy from PCN-224 surface to the whole system.With the unique SA recognition and the mediation of Ce^(3+),both the photocurrent and the visualization signals sensitively responded with the SA concentration linearly.The present method showed greatly high sensitivity,selectivity and accuracy for SA detection with a limit of detection of 1.44μmol/L and a wide linear range of 5-1000μmol/L.This method provided a new promising platform for SA detection and a potential strategy for design of novel biosensors with dual-model readout.展开更多
Industrial production of NH3 from N2 and H2 significantly relies on Haber-Bosch process,which suffers from high energy consume and CO2 emission.As a sustainable and environmentally-benign alternative process,electroch...Industrial production of NH3 from N2 and H2 significantly relies on Haber-Bosch process,which suffers from high energy consume and CO2 emission.As a sustainable and environmentally-benign alternative process,electrochemical artificial N2 fixation at ambient conditions,however,is highly required efficient electrocatalysts.In this study,we demonstrate that hexagonal boron nitride nanosheet (h-BNNS) is able to electrochemically catalyze N2 to NH3.In acidic solution,h-BNNS catalyst attains a high NH3 formation rate of 22.4 μg·h-1·mg-1cat.and a high Faradic efficiency of 4.7% at-0.75 V vs.reversible hydrogen electrode,with excellent stability and durability.Density functional theory calculations reveal that unsaturated boron at the edge site can activate inert N2 molecule and significantly reduce the energy barrier for NH3 fonmation.展开更多
Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu2O nanowire array(CuO/Cu2O Nanowire) supported on copper foam was prepa...Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu2O nanowire array(CuO/Cu2O Nanowire) supported on copper foam was prepared as a photocathode for detection of tyrosinase though quinone-chitosan conjugation chemistry method. The in-situ generated quinones that were the catalytic product of tyrosinase acted as electron acceptors, which were captured by the chitosan deposited on the surface of the electrode. Direct immobilization of electron acceptor on the electrode surface improved the photocurrent conversion efficiency and thus sensitivity. The as-prepared biosensor can realize a rapid response in a wide linear range of 0.05 U/mL to 10 U/mL with the detection limit as low as 0.016 U/mL of tyrosinase. The current work provides a new perspective to design and develop highly sensitive and selective PEC biosensor.展开更多
基金supported by grants awarded by the National Natural Science Foundation of China(Nos.21505084,21775089)Natural Science Foundation Projects of Shandong Province(No.ZR2014BM029)+2 种基金Key Research and Development Program of Shandong Province(No.2017GSF19109)Innovation Project of Shandong Graduate Education(No.SDYY16091)Outstanding Youth Foundation of Shandong Province(No.ZR2017JL010)。
文摘In this research,a hydroxyl group functionalized metal-organic framework(MOF),UiO-66-(OH)_(2),was synthesized as a "on-off-on" fluore scent switching nanoprobe for highly sensitive and selective detection of Fe^(3+),ascorbic acid(AA) and acid phosphatase(ACP).UiO-66-(OH)_(2) emits yellow-green light under ultraviolet light,when Fe^(3+) was added,Fe^(3+) was chelated with hydroxyl group,the electrons in the excited state S_1 of the MOF transferred to the half-filled 3 d orbits of Fe^(3+),resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation.AA could reduce Fe^(3+) to Fe^(2+),which can destroy the electron transfer between UiO-66-(OH)_(2) and Fe^(3+) after AA adding,resulted in nonoccurrence of the nonradiative electron transfer,leading to the recovery of UiO-66-(OH)_(2) fluorescence intensity.The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-L-ascorbic acid(AAP) to produce AA.Benefitting from the hydroxyl group and the characteristics of UiO-66,including the high porosity and large surface area,the developed UiO-66-(OH)_(2) showed extensive advantages as a fluorescent probe for detection of multi-component,such as high sensitivity and selectivity,colorimetric detection,fast response kinetics and easy to operate,economical and secure.This is the first time to use active group functionalized MOFs as a multicomponent sensor for these three substances detection.
基金supported by grants awarded by the National Natural Science Foundation of China(Nos.22174086,21775089 and 22074080)Changjiang Scholar Program of the Ministry of Education of China(No.Q2019258)+2 种基金Natural Science Foundation of Shandong Province(Nos.ZR2020MB056 and ZR2020KB020)Taishan Scholar Program of Shandong Province(No.tsqn201909106)College Students Innovation and Entrepreneurship Training Project of Shandong Province(No.S201910446019)。
文摘Development of sensitive and accurate methods for sialic acid(SA) determination is of great significance in early cancer diagnosis.Here,a colorimetric-assisted Photoelectrochemical(PEC) sensor was constructed for SA detection based on the two pairs of cis-diol groups in SA molecule.With the specific recognition of SA via the two pairs of cis-diol groups,the prepared gold-modified Bi_(2)S_(3)(AuNPs@Bi_(2)S_(3)) and metal organic framework(Au@PCN-224) were introduced to the electrode and formed a sandwich structure.Based on the properties of inert electroconductivity and nanozyme of the PCN-224,dual-readout of photocurrent and visualization was achieved with the presence of 3',3',5',5'-tetramethylbenzidine(TMB).Moreover,to intensify the visualization signal,Ce^(3+) was employed as the mediator to boost the catalysis capability by transferring energy from PCN-224 surface to the whole system.With the unique SA recognition and the mediation of Ce^(3+),both the photocurrent and the visualization signals sensitively responded with the SA concentration linearly.The present method showed greatly high sensitivity,selectivity and accuracy for SA detection with a limit of detection of 1.44μmol/L and a wide linear range of 5-1000μmol/L.This method provided a new promising platform for SA detection and a potential strategy for design of novel biosensors with dual-model readout.
基金National Natural Science Foundation of China (Nos. 21575137, 21775089, and 21375076)Key Research and Development Program of Shandong Province (No. 2015GSF121031)Natural Science Foundation Projects of Shandong Province (Nos. ZR2017JL010, ZR2017QB00& and ZR2017LEE006).
文摘Industrial production of NH3 from N2 and H2 significantly relies on Haber-Bosch process,which suffers from high energy consume and CO2 emission.As a sustainable and environmentally-benign alternative process,electrochemical artificial N2 fixation at ambient conditions,however,is highly required efficient electrocatalysts.In this study,we demonstrate that hexagonal boron nitride nanosheet (h-BNNS) is able to electrochemically catalyze N2 to NH3.In acidic solution,h-BNNS catalyst attains a high NH3 formation rate of 22.4 μg·h-1·mg-1cat.and a high Faradic efficiency of 4.7% at-0.75 V vs.reversible hydrogen electrode,with excellent stability and durability.Density functional theory calculations reveal that unsaturated boron at the edge site can activate inert N2 molecule and significantly reduce the energy barrier for NH3 fonmation.
基金supported by the National Natural Science Foundation of China (21775089)the Outstanding Youth Foundation of Shandong Province (ZR2017JL010)+1 种基金the Key Research and Development Program of Jining City (2018ZDGH032)Taishan scholar of Shandong Province (tsqn201909106)。
文摘Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu2O nanowire array(CuO/Cu2O Nanowire) supported on copper foam was prepared as a photocathode for detection of tyrosinase though quinone-chitosan conjugation chemistry method. The in-situ generated quinones that were the catalytic product of tyrosinase acted as electron acceptors, which were captured by the chitosan deposited on the surface of the electrode. Direct immobilization of electron acceptor on the electrode surface improved the photocurrent conversion efficiency and thus sensitivity. The as-prepared biosensor can realize a rapid response in a wide linear range of 0.05 U/mL to 10 U/mL with the detection limit as low as 0.016 U/mL of tyrosinase. The current work provides a new perspective to design and develop highly sensitive and selective PEC biosensor.
