Synergistic AuNPs@CuMOF for Electrochemical Amplified Detection of Neuron-Specific Enolase

Signal amplification has become a paramount strategy in biosensing, offering substantial improvements in sensitivity and detection limits for analytical platforms. However, conventional methods often rely on separate amplification stages and intricate chemical functionalization, leading to inefficiencies and greater complexity in biosensing workflows. In this article, we introduce a novel dual-purpose application of AuNPs@CuMOF for both surface functionalization and signal amplification, enabling electrochemical biosensing of neuron-specific enolase (NSE), a key biological marker for neuronal disorders and small cell lung cancer. The proposed biosensing strategy implies immobilizing the biotinylated NSE antibody onto the AuNPs@CuMOF-functionalized surface of a screen-printed carbon electrode (SPCE), alongside a thiolated NSE aptamer conjugated to AuNPs@CuMOF for signal amplification. Following this approach, the proposed immunosensor showcased a detection limit (LOD) down to 0.02 pg/mL within the span of 0.1 pg/mL to 200 ng/mL, outperforming or matching previously reported NSE biosensors. Besides, the suggested NSE biosensor reliably identified NSE in spiked human serum samples, showing both strong selectivity and sensitivity, with performance metrics on par with those of standard ELISA tests, with the relative error ranging from 12.03% to 5.63%. By leveraging the combined advantages of CuMOF's large surface area, versatility, and stability, the proposed method simplifies the biosensing workflow while enhancing sensitivity through intrinsic amplification, resulting in a robust and efficient platform for the detection of biomarkers. We highlight in this work the transformative potential of multifunctional nanomaterials in advancing electrochemical biosensing technologies, wihch represents a significant milestone in tumor diagnosis in clinical settings.