title: Signal-on CoA-dependent electrochemical biosensor for highly sensitive and label-free detection of Citrate synthase activity.
abstract: We report here a label-free and sensitive electrochemical method for probing Citrate synthase (CS) activity based on detailed investigations into the nucleic acid-mimicking coordination polymer (CP) formed from the coenzyme A (CoA)-Ag(I) repeat units. Our biosensing approach provides an especial and significant detection mechanism: CS can catalyze the essential condensation reaction between acetyl-coenzyme A (Ac-CoA) and oxaloacetate (OAA) to form citrate and CoA; then, in the presence of Ag(I), CoA-Ag(I) CP can be in situ formed because of the strong complexation ability of thiol groups of CoA toward Ag(I). The generated CoA-Ag(I) CP attaches to graphene-modified glassy carbon electrode surface by multiple adenine bases deriving from CoA and acting as the side groups along the polymeric backbone, which displays efficient H2O2-electrocatalyzing activity. More importantly, by using the formed polymer as signal output, the process is implemented to quantitatively analyze the activity of CS. Under the optimal conditions, CS with a detection limit as low as 0.00165U/µL could be sensitively probed with a wide linear range from 0.0033 to 0.264U/µL. Furthermore, with the character of label-free detection, high sensitivity and excellent selectivity, this strategy offers a convenient and specific method for CS activity detection and relevant inhibitors screening, which holds a promising potential in the practical application of CS-based biochemical research, disease diagnosis and drug discovery.
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 PR China.
authors: Qin
authors: Q
authors: Wang
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 PR China.
authors: Hongjun
authors: H
authors: Chen
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 PR China.
authors: Yong
authors: Y
authors: Li
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 PR China.
authors: Huixia
authors: H
authors: Wang
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 PR China. Electronic address: niezhou.hnu@gmail.com.
authors: Zhou
authors: Z
authors: Nie
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211 PR China. Electronic address: huyufang@nbu.edu.cn.
authors: Yufang
authors: Y
authors: Hu
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 PR China.
authors: Shouzhou
authors: S
authors: Yao
mesh_terms: D015374:Biosensing Techniques; D002384:Catalysis; D002950:Citrate (si)-Synthase / Q000737:chemistry*; D003065:Coenzyme A / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D012834:Silver / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D010087:Oxides; D012834:Silver; D006108:Graphite; D006861:Hydrogen Peroxide; D002950:Citrate (si)-Synthase; D003065:Coenzyme A
keywords: Citrate synthase; CoA-Ag(I) coordination polymer; Electrochemical sensor; Graphene; Inhibitor