MIP based sensor for detection of gut microbiota-derived Indoxyl Sulfate using PANI- Graphene-NiS2.

Abstract

Indoxyl sulphate (IS) is a gut microbiota-derived metabolite that is involved in human health and dis- eases. The normal range of IS in human serum may be in the range of 0.024e0.05 mg/dl, but the altered IS level has been observed in diseased conditions, such as chronic kidney diseases, diabetes and cancer, which implicate IS as a diagnostic and prognostic biomarker. In the current work, a molecularly imprinted polymer (MIP)-based electrochemical sensor was made for the quantification of IS in a wide concentration range. The IS sensing was studied using DPV, revealing decreasing peak current with increasing IS concentrations. The MIP/ITO electrode has shown a good response from 1.0 pM to 6.0 mM which is linear in trend, with a sensitivity of 0.0362 mA (log (ng/mL)) -1 cm -2 and a lower limit of detection of 0.286 pg/mL and a low response time of 5 min. The interference study also confirmed the specificity of MIP-based electrochemical sensor toward IS detection. The real sample study confirmed the MIP-based sensor's applicability to detect IS in urine samples. The sensitive, cheap, and reproducible MIP-based detection of IS may offer a new diagnostic approach to diagnose various diseases implicated with altered level of IS in human serum and urine.