A label-free"light-on"colorimetric assay for ascorbic acid(AA)determination is unprecedentedly devised by regulating the intrinsic peroxidase-mimetic activity of the Fe-MIL-88.AA can reduce Fe(Ⅲ)presented i...A label-free"light-on"colorimetric assay for ascorbic acid(AA)determination is unprecedentedly devised by regulating the intrinsic peroxidase-mimetic activity of the Fe-MIL-88.AA can reduce Fe(Ⅲ)presented in Fe-MIL-88 to Fe(Ⅱ),which will dramatically promote the hydroxyl radicals(·OH)conversion efficiency of H_(2)O_(2)through a Fenton reaction,and effectually accelerate the Fe-MIL-88 catalyzed chromogenic reaction of 3,3′,5,5′-tetramethylbenzidine(TMB)-H_(2)O_(2).Redox reaction between AA and H_(2)O_(2)also can produce·OH and promote this chromogenic reaction.Thus,quantification of AA is real-ized via determining the enhanced colorimetric signals.The linear range is 0.5−40μM with a detection limit of 0.12μM.Furthermore,the straightforward yet effective colorimetric strategy with the merits of simplicity,cost-effectiveness,high accuracy,specificity,and sensitivity is widely utilized to determine the concentrations of AA in serological tests.展开更多
The application of metal-organic frameworks(MOFs)nanozymes in biosensing has been extensively investigated,however,till now there is still no report on photoelectrochemical(PEC)sensing based on enzyme memetic properti...The application of metal-organic frameworks(MOFs)nanozymes in biosensing has been extensively investigated,however,till now there is still no report on photoelectrochemical(PEC)sensing based on enzyme memetic properties of MOFs.To further expand the utilization of MOFs nanozymes in biosensing,we developed a label-free homogenous PEC aptasensor for the detection of VEGF_(165),an important cancer biomarker,based on the DNA-regulated peroxidase-mimetic activity of Fe-MIL-88,a type of MOFs.In this strategy,the peroxidase-mimetic property of MOFs is integrated with the label-free homogeneous PEC sensing approach,and highly sensitive detection of VEGF_(165)is obtained with a detection limit down to 33 fg/m L,superior or comparable to the previously reported values.Moreover,this approach displays outstanding specificity,and has been successfully used to detect VEGF_(165)added in diluted serum samples.As far as we know,it is the first example to employ the peroxidase-like activity of MOFs in PEC biosensing,which may find potential application in bioanalysis and early disease diagnosis.展开更多
基金supported by the National Natural Science Foundation of China(21904048,21902061 and 21902062)the Natural Science Foundation of Shandong Province(ZR2019YQ10 and ZR2020QB033)the Young Taishan Scholars Program(tsqn201812080).
文摘A label-free"light-on"colorimetric assay for ascorbic acid(AA)determination is unprecedentedly devised by regulating the intrinsic peroxidase-mimetic activity of the Fe-MIL-88.AA can reduce Fe(Ⅲ)presented in Fe-MIL-88 to Fe(Ⅱ),which will dramatically promote the hydroxyl radicals(·OH)conversion efficiency of H_(2)O_(2)through a Fenton reaction,and effectually accelerate the Fe-MIL-88 catalyzed chromogenic reaction of 3,3′,5,5′-tetramethylbenzidine(TMB)-H_(2)O_(2).Redox reaction between AA and H_(2)O_(2)also can produce·OH and promote this chromogenic reaction.Thus,quantification of AA is real-ized via determining the enhanced colorimetric signals.The linear range is 0.5−40μM with a detection limit of 0.12μM.Furthermore,the straightforward yet effective colorimetric strategy with the merits of simplicity,cost-effectiveness,high accuracy,specificity,and sensitivity is widely utilized to determine the concentrations of AA in serological tests.
基金funded by the National Natural Science Foundation of China(Nos.22174083 and 22076090)Shandong Provincial Natural Science Foundation(No.ZR2020ZD37)Shandong Province Higher Educational Program for Young Innovation Talents。
文摘The application of metal-organic frameworks(MOFs)nanozymes in biosensing has been extensively investigated,however,till now there is still no report on photoelectrochemical(PEC)sensing based on enzyme memetic properties of MOFs.To further expand the utilization of MOFs nanozymes in biosensing,we developed a label-free homogenous PEC aptasensor for the detection of VEGF_(165),an important cancer biomarker,based on the DNA-regulated peroxidase-mimetic activity of Fe-MIL-88,a type of MOFs.In this strategy,the peroxidase-mimetic property of MOFs is integrated with the label-free homogeneous PEC sensing approach,and highly sensitive detection of VEGF_(165)is obtained with a detection limit down to 33 fg/m L,superior or comparable to the previously reported values.Moreover,this approach displays outstanding specificity,and has been successfully used to detect VEGF_(165)added in diluted serum samples.As far as we know,it is the first example to employ the peroxidase-like activity of MOFs in PEC biosensing,which may find potential application in bioanalysis and early disease diagnosis.
