Molecularly imprinted sensor for lipoic acid quantification in serum: a proof-of-concept for diagnosis of NELL-1 membranous nephropathy and kidney failure

Abstract

Sensitive quantification of α-lipoic acid (LA) in human serum is essential for early detection and monitoring of kidney disorders but remains challenging due to interference from complex biological matrices. Here, we report an electrochemical sensor using a molecularly imprinted poly(aniline-co-m-aminophenol) (MIP) copolymer engineered with porous morphology and low interfacial resistance to enhance charge transfer and selective analyte recognition. Cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy confirm efficient charge transfer, diffusion-controlled kinetics, and a clear analytical response toward LA across 0–500 μM, achieving high sensitivity (2.04 μA cm⁻² μM⁻¹) and a detection limit of 189 nM. The sensor demonstrates a mean recovery of 102 ± 7.07% in spiked human serum, validating reliable performance under clinically relevant conditions. This work establishes a practical platform for rapid, accurate, and sensitive LA detection, supporting point-of-care diagnostics and continuous monitoring in biomedical applications.