Electrochemical detection of procaine hydrochloride anesthetic using diamond-graphene composite electrodes

Abstract

This research presents a new electrochemical sensor that can detect procaine hydrochloride and p-aminobenzoic acid (PABA) at the same time. The sensor is based on a diamond-graphene composite electrode modified with MWCNTs. The sensor was fabricated through an innovative sp3-to-sp2 conversion process and optimized MWCNT loading. Electrochemical characterization revealed enhanced electron transfer kinetics and a 3-fold increase in peak currents compared to bare diamond electrodes. The sensor exhibited wide linear ranges (0.1–100 μM for procaine, 0.05–80 μM for PABA) and low detection limits (30 nM and 15 nM, respectively). Excellent selectivity was achieved with 95 % signal retention after 30 days). Analysis of spiked human plasma samples yielded recoveries of 97.2–103.5 % (RSD <4.5 %). Application to pharmaceutical formulations showed agreement with labeled amounts (98.5–101.2 % recovery) and detected 0.031 % PABA in a topical cream. This sensor offers a simple, sensitive, and reliable approach for procaine and PABA determination in complex matrices, outperforming many existing methods in terms of sensitivity and simultaneous detection capabilities.

Keywords

• Carbon nanomaterials
• Electrochemical sensor
• Local anesthetic
• Metabolite detection
• Pharmaceutical analysis