Heterostructure nanozyme-synergistically modulated electrochemiluminescence/photoelectrochemical sensing platform for detection of Alzheimer's disease biomarkers in plasma samples.

In this work, a PtPd/CeO2 heterostructure nanozyme-synergistically modulated ternary ZnS/CdS/Bi2Se3 electrochemiluminescence/photoelectrochemical (ECL/PEC) aptasensor was designed for simultaneous detection of amyloid-β peptides (Aβ1-40 and Aβ1-42), as the key plasma biomarkers of Alzheimer's disease (AD). Benefiting from the bimetallic alloy effect and the support-active component synergy, PtPd/CeO2 heterostructure efficiently accelerated interfacial electron transfer, leading to both an improved catalytic reaction kinetic rate and enhanced adsorption and activation of reactants. Ternary ZnS/CdS/Bi2Se3 achieved photocurrent self-enhancement via synergistic bandgap excitation and multi-interface charge transfer effects among its components, thereby significantly boosting the response signals of both ECL and PEC. Through the integration of aptamer-mediated specific target recognition and toehold-triggered strand displacement reaction (TSDR)-based signal amplification, this aptasensor realized the simultaneous detection of Aβ1-42 and Aβ1-40. Notably, practical validation of the aptasensor for Aβ1-42/Aβ1-40 ratio detection in actual plasma specimens demonstrated the feasibility of minimally invasive liquid biopsy with high patient compliance and great potential for large-scale screening and early diagnosis of AD.