Development of a molecularly imprinted electrochemical sensor for the rapid detection of lactate

Abstract

Background

Lactate is an important biomarker for monitoring metabolic conditions and is widely used as an indicator in clinical diagnostics. It plays a critical role in the early diagnosis and monitoring of neonatal sepsis, where elevated lactate levels indicate tissue hypoxia and metabolic imbalance. Conventional detection methods often involve enzymatic systems, which may suffer from stability and reproducibility issues.

Objective

This study aims to develop a reagent-free, non-enzymatic molecularly imprinted electrochemical sensor for the selective detection of lactate.

Methods

A screen-printed electrode (SPE) was modified with reduced graphene oxide (RGO) and gold nanoparticles (AuNP) via electrodeposition. A molecularly imprinted polymer (MIP) layer was fabricated through electropolymerization of 3-aminophenylboronic acid (3-APBA) in the presence of lactic acid as the template. The stepwise fabrication, including template removal and rebinding, was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Sensor performance was evaluated using differential pulse voltammetry (DPV).

Results

The sensor exhibited a linear response to lactate over the range of 0.05 µM to 6.0 mM, with a limit of detection (LOD) of 0.361 µM. The MIP sensor demonstrated high selectivity against common interfering species, including glucose, urea, ascorbic acid, and acetic acid, along with good reproducibility and stability.

Conclusion

The developed reagent-free, non-enzymatic MIP-based sensor provides a simple and effective platform for selective lactate detection, with potential applicability to clinical monitoring, following further validation on real samples.