Ultrasensitive dual-signal ratiometric electrochemical aptasensor for neuron-specific enolase based on Au nanoparticles@Pd nanoclusters-poly(bismarck brown Y) and dendritic AuPt nanoassemblies

Abstract Neuron-specific enolase (NSE) is viewed as a tumor marker of small cell lung cancer (SCLC) with high diagnostic sensitivity and specificity, whose facile and sensitive detection is critical for clinical diagnosis. In this work, core-shell Au nanoparticles @Pd nanoclusters-poly(bismarck brown Y) (Au@Pd-P(BBY)) and hierarchically dendritic AuPt nanoassemblies (AuPt NAs) were synthesized independently by a one-pot aqueous method. A dual-signal ratiometric electrochemical aptasensor was developed for ultrasensitive determination of NSE based on ferrocene grafted Au@Pd-P(BBY) (Fc-g-Au@Pd-P(BBY)) and reduced graphene oxide/thionine decorated AuPt NAs (rGO/Thi/AuPt NAs). Under optimal conditions, the changes in the peak currents linearly correlate to the NSE concentrations in the wide range of 0.0001―50.0 ng mL–1 with ultralow detection limit (0.03 pg mL–1, S/N = 3). The aptasensor was explored in a diluted human serum sample with acceptable results, showing its great potential in clinical diagnosis and treatment.