Biocompatible self-assembled monolayer platform based on (3-glycidoxypropyl)trimethoxysilane for total cholesterol estimation

Abstract

An electrochemical cholesterol biosensor has been fabricated via covalent immobilization of cholesterol oxidase and cholesterol esterase (ChOx and ChEt) onto a biocompatible self assembled monolayer (SAM) of (3-glycidoxypropyl)trimethoxysilane (GPTMS) fabricated onto an indium tin oxide (ITO) electrode. The ChOx/GPTMS/ITO bioelectrode has been characterized using Fourier transform infrared spectroscopy (FTIR), contact angle measurements (CA), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) techniques. The results of the electrochemical response studies indicate that the ChOx-ChEt/GPTMS/ITO biosensing electrode can be used to estimate the total cholesterol from 1.5 to 6.1 mM, has sensitivity of 0.351 mA (mg/dl) À1, and can be used more than 10 times with a shelf life of up to 10 weeks. The value of the MichaelisMenten constant (K m ) observed as 0.43 mM reveals a strong binding to the biocompatible GPTMS organic platform and shows low interference effect. Further, this biosensor can be used to estimate the total cholesterol concentration in serum samples.

Cholesterol Self-Powered Biosensor

“…Different design strategies have been utilised for the development of electrochemical cholesterol biosensors including oxidation by mediated ChOx [5][6][7][8][9][10] or hydrogen peroxide monitoring by horse radish peroxidase 11,12 or by inorganic catalysts 13 and nanostructures [14][15][16] . Despite of the variety of reported cholesterol electrochemical biosensors 4 , only few of them have been shown to operate in whole blood [17][18][19] . An amperometric biosensor based on ChOx entrapped inside a composite polypyrrole-hydrogel membrane showed excellent correlation with results obtained by the standard method 17 for total cholesterol determination in cholesterol esterase (ChEt) pretreated serum samples.…”

“…An amperometric biosensor based on ChOx entrapped inside a composite polypyrrole-hydrogel membrane showed excellent correlation with results obtained by the standard method 17 for total cholesterol determination in cholesterol esterase (ChEt) pretreated serum samples. Kumar et al have developed an electrochemical biosensor, based on covalent coimmobilisation of ChOx and ChEt onto an electrode modified with a biocompatible self-assembled monolayer for total cholesterol quantification in undiluted serum samples 18 . Zhu et al have reported a biosensor based on direct electron transfer of ChOx immobilised on multiwalled carbon nanotubes decorated with gold nanoparticles for free cholesterol measurements in entire human serum 19 .…”

Tribology and hydrophobicity of a biocompatible GPTMS/PFPE coating on Ti6Al4V surfaces

“…In one of the study, noncytotoxicity of GPTMS was validated by the assessment of cytocompatibility of hybrids of gelatin-GPTMS and chitosan-GPTMS in an in-vitro study (Ren et al, 2002a). In another study, biocompatibility of GPTMS SAM was confirmed using both bacterial culture (E.coli DH5a, Gram negative bacteria) and plant tissue culture (wheat seed) (Kumar et al, 2011).…”

Surface protection of copper by allyl thiourea and hybrid sol–gel coatings

“…Furthermore, the reduction wave intensity was decreased to a large extent. These observations indicated that Hy monolayers were successfully grafted over ATU/Cu surface [40][41][42]. …”