Ru–Au nanocluster-functionalized carbon fiber microelectrode enables ultrasensitive multiplexed monitoring of acetaminophen and its genotoxic interplay with DNA

This study presents the development of a highly sensitive and selective electrochemical sensor based on ruthenium-gold nanocluster-functionalized carbon fiber microelectrodes (AuNPs/RuNPs/CFME) for the ultrasensitive detection of acetaminophen (ACOP) and its genotoxic impurities, <i>p</i>-aminophenol (PAP) and <i>p</i>-nitrophenol (PNP). Leveraging the synergistic electrocatalytic effects of bimetallic nanoparticles, the modified electrode demonstrated exceptional performance, achieving wide linear ranges (0.04-100 µmol L^-1 for ACOP, 1-10 µmol L^-1 for PAP and PNP) and remarkably low detection limits (6.192 nmol L^-1 for ACOP, 0.19 µmol L^-1 for PAP, and 0.015 µmol L^-1 for PNP). The sensor exhibited outstanding stability, anti-interference capability, and successful application in human serum samples with recoveries of 95.9-100.5%. Furthermore, the study explored the genotoxic interaction between ACOP and double-stranded DNA (dsDNA) using electroanalytical, UV spectrophotometric, and molecular docking techniques. Results revealed that ACOP intercalates into dsDNA <i>via</i> hydrogen bonding and π-π stacking, providing mechanistic insights into its hepatotoxicity at high concentrations. The proposed sensor not only offers a robust platform for multiplexed drug monitoring but also advances understanding of ACOP-induced DNA damage, highlighting its potential in pharmacokinetic studies and toxicity assessment. This work underscores the significance of nanomaterial-enhanced electrochemical sensors for pharmaceutical quality control and toxicity assessment.