By adjusting the coordination environment of single-atom catalysts,the enzyme-like activity can be finely tuned for highly sensitive biosensing.Herein,we demonstrated that coordinatively unsaturated cobalt-nitrogen si...By adjusting the coordination environment of single-atom catalysts,the enzyme-like activity can be finely tuned for highly sensitive biosensing.Herein,we demonstrated that coordinatively unsaturated cobalt-nitrogen sites doped within porous carbon(SA-CoN_(3))could serve as highly efficient oxidase mimic.Compared with the typical planar four-coordination structure(SA-CoN_(4)),the as-obtained single-atom Co nanozymes anchored by three nitrogen atoms are found to display much higher oxidase-like catalytic efficiency.Combined theoretical and experimental analysis revealed that the coordinatively unsaturated Co sites could facilitate adsorption and activation of O_(2) molecule and thus improve their oxidase-like activity.Based on the enhanced oxidase-like activity of SA-CoN_(3),a paper/smartphone sensor for organophosphorus pesticides(OPs)was successfully constructed and used to quantify glyphosate in environmental and food samples with a low detection limit of 0.66μM.This work not only highlights the important role of coordination unsaturation of SA nanozymes for promoting oxidase-like activity,but also provides an easy and cost-effective way to conduct effective quantification of OPs in the field.展开更多
Nanozymes are nanomaterials with intrinsic enzyme-mimic activity,but their large-scale application is generally limited by their low catalytic activity.Herein,we demonstrated that highly exposed Cu active sites on two...Nanozymes are nanomaterials with intrinsic enzyme-mimic activity,but their large-scale application is generally limited by their low catalytic activity.Herein,we demonstrated that highly exposed Cu active sites on two-dimensional(2D)nitrogen-doped carbon(Cu_(x)/NC)can serve as efficient peroxidase-like(POD)catalysts with high atomic utilization.Specially,the uniformly distributed Cu active sites could react with H_(2)O_(2)to produce singlet oxygen(^(1)O_(2))under acidic conditions,which can efficiently oxidizes colorless 3,3',5,5'-tetramethylbenzidine(TMB)to blue oxidized TMB(oxTMB).Among various Cu_(x)/NC nanozymes studied,the Cuo.14/NC exhibited smaller maximum catalytic velocities(V_(max))and Menten constant(K_(m))for TMB and H_(2)O_(2).Benefiting from the highly active peroxidase-like activity,the Cu_(0.14)/NC nanozyme could be successfully applied for the hydroquinone(HQ)and ascorbic acid(AA)detection applications through the inhibitory effect of HQ and AA.More interestingly,α-glucosidase(α-Glu)detection sensing platform could be constructed based on HQ as a signal transmitter,with the detection range ranging from O to 12 U/L and the minimum detection limit being 0.68 U/L.This work provides not only an idea for the rational design of highly exposed Cu active sites but also fabricate an effective detection sensing platform forHQ,AA,andα-Glu detection.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22172063 and 21904048)the Young Taishan Scholar Program(No.tsqn201812080)the Independent Cultivation Program of Innovation Team of Ji’nan City(No.2021GXRC052).
文摘By adjusting the coordination environment of single-atom catalysts,the enzyme-like activity can be finely tuned for highly sensitive biosensing.Herein,we demonstrated that coordinatively unsaturated cobalt-nitrogen sites doped within porous carbon(SA-CoN_(3))could serve as highly efficient oxidase mimic.Compared with the typical planar four-coordination structure(SA-CoN_(4)),the as-obtained single-atom Co nanozymes anchored by three nitrogen atoms are found to display much higher oxidase-like catalytic efficiency.Combined theoretical and experimental analysis revealed that the coordinatively unsaturated Co sites could facilitate adsorption and activation of O_(2) molecule and thus improve their oxidase-like activity.Based on the enhanced oxidase-like activity of SA-CoN_(3),a paper/smartphone sensor for organophosphorus pesticides(OPs)was successfully constructed and used to quantify glyphosate in environmental and food samples with a low detection limit of 0.66μM.This work not only highlights the important role of coordination unsaturation of SA nanozymes for promoting oxidase-like activity,but also provides an easy and cost-effective way to conduct effective quantification of OPs in the field.
基金supported by the National Natural Science Foundation of China(22172063)the Young Taishan Scholar Program(tsqn201812080)the Independent Cultivation Program of Innovation Team of Jinan City(2021GXRC052).
文摘Nanozymes are nanomaterials with intrinsic enzyme-mimic activity,but their large-scale application is generally limited by their low catalytic activity.Herein,we demonstrated that highly exposed Cu active sites on two-dimensional(2D)nitrogen-doped carbon(Cu_(x)/NC)can serve as efficient peroxidase-like(POD)catalysts with high atomic utilization.Specially,the uniformly distributed Cu active sites could react with H_(2)O_(2)to produce singlet oxygen(^(1)O_(2))under acidic conditions,which can efficiently oxidizes colorless 3,3',5,5'-tetramethylbenzidine(TMB)to blue oxidized TMB(oxTMB).Among various Cu_(x)/NC nanozymes studied,the Cuo.14/NC exhibited smaller maximum catalytic velocities(V_(max))and Menten constant(K_(m))for TMB and H_(2)O_(2).Benefiting from the highly active peroxidase-like activity,the Cu_(0.14)/NC nanozyme could be successfully applied for the hydroquinone(HQ)and ascorbic acid(AA)detection applications through the inhibitory effect of HQ and AA.More interestingly,α-glucosidase(α-Glu)detection sensing platform could be constructed based on HQ as a signal transmitter,with the detection range ranging from O to 12 U/L and the minimum detection limit being 0.68 U/L.This work provides not only an idea for the rational design of highly exposed Cu active sites but also fabricate an effective detection sensing platform forHQ,AA,andα-Glu detection.