title: Reusable and mediator-free cholesterol biosensor based on cholesterol oxidase immobilized onto TGA-SAM modified smart bio-chips.
abstract: A reusable and mediator-free cholesterol biosensor based on cholesterol oxidase (ChOx) was fabricated based on self-assembled monolayer (SAM) of thioglycolic acid (TGA) (covalent enzyme immobilization by dropping method) using bio-chips. Cholesterol was detected with modified bio-chip (Gold/Thioglycolic-acid/Cholesterol-oxidase i.e., Au/TGA/ChOx) by reliable cyclic voltammetric (CV) technique at room conditions. The Au/TGA/ChOx modified bio-chip sensor demonstrates good linearity (1.0 nM to 1.0 mM; R = 0.9935), low-detection limit (∼0.42 nM, SNR∼3), and higher sensitivity (∼74.3 µA µM(-1) cm(-2)), lowest-small sample volume (50.0 μL), good stability, and reproducibility. To the best of our knowledge, this is the first statement with a very high sensitivity, low-detection limit, and low-sample volumes are required for cholesterol biosensor using Au/TGA/ChOx-chips assembly. The result of this facile approach was investigated for the biomedical applications for real samples at room conditions with significant assembly (Au/TGA/ChOx) towards the development of selected cholesterol biosensors, which can offer analytical access to a large group of enzymes for wide range of biomedical applications in health-care fields.
authors.affiliation: Chemistry Department & Center of Excellence for Advanced Materials Research (CEAMR), Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Mohammed M
authors.initials: MM
authors.lastname: Rahman
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002138:Calibration; D002784:Cholesterol / Q000032:analysis* / Q000737:chemistry; D002789:Cholesterol Oxidase / Q000737:chemistry* / Q000378:metabolism; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D017743:Equipment Reuse; D057230:Limit of Detection; D015203:Reproducibility of Results; D013864:Thioglycolates / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D013864:Thioglycolates; C017487:2-mercaptoacetate; D002784:Cholesterol; D002789:Cholesterol Oxidase