Electrochemical Process of Immuno-Based Thinonine Doped Nanosilica Electrode Modification and Its Use as an Enzymatic Sensor For Electrochemical Detection of Platelet Hyperactivity

We report here design of a thionine doped silica nanocomposite (TH@SiO2) based electrochemical biosensor for the detection of platelet-derived nanoparticles (PMPs), a major risk factor for platelet hyperactivity that plays lead role in cardiovascular diseases like acute myocardial infarction and stroke. TH@SiO2 was deposited on indium tin oxide (ITO) electrode by two-step electropolymerisation. TH@SiO2 has property of facilitating fast electron transfer between horse radish peroxidase (HRP) and the electrode surface as compared to thionine film. The deposited film represents a novel enzyme immobilisation matrix for the detection of PMPs. Electrodes were fabricated with immobilized layers of TH@SiO2 and then nanosilica film was conjugated with a PAC1 antibodies specifically targeted against PMPs by covalent bond. Simultaneously, amine modified mesoporous silica (NH2-MSNs), MCM-41 was synthesized and conjugated covalently with P-selectin antibodies (other specific marker of platelet activation) and then HRP was entrapped in the pores of NH2-MSNs by simple adsorption method. Results showed progressive increase in reduction current in cyclic voltammetry with increased counts of PMPs in electrolyte buffer on addition of hydrogen peroxide. The sensor was highly specific for PMPs and did not identify microparticles originating from other cells. Thus, this electrochemical biosensor offers a specific, sensitive, label-free, cost-effective, qualitative as well as quantitative tool for rapid point-of-care detection of platelet hyperactivity at bedside.

Filed by:

1). Dr. Sunil Kumar

2). Ms.  Priti Singh

3). Prof. P.  Chakrabarti