Disposble electrochemical aptasensors: From design strategies, signal amplification, to applications and future perspectives.

Disposable electrochemical aptasensors (DEAs) hold significant promise for different analyte detection across diverse fields, due to inherent advantages of rapid response, portability, low cost, and high sensitivity. This review systematically examines the design strategies, signal amplification methodologies, and recent advances in DEAs in the fields of environmental analysis, food safety monitoring, and medical diagnostics. Specifically, it critically evaluates construction strategies for screen-printed electrodes (SPEs) and paper-based electrodes, including substrate selection, ink formulations, and key fabrication techniques such as screen printing, inkjet printing, deposition methods, and direct-writing technologies. The analysis further explores core signal amplification strategies-including nanomaterial-enhanced transduction, enzymatic catalysis, exonuclease-assisted target recycling, and multimodal synergistic amplification, which collectively achieve significantly lowered detection limit through enhanced electron transfer efficiency and catalytic activity. Compared to unamplified systems, these strategies typically enable detection limits down to the picomolar (pM) or even femtomolar (fM) range, enhance sensitivity by orders of magnitude, and significantly improve the sensor's robustness against matrix interference, thereby enabling reliable detection of trace analytes in actual samples. Representative applications in environmental monitoring, food safety, and medical diagnostics are highlighted, demonstrating high selectivity and practical utility in complex matrices. Despite advantages including cost-effectiveness, portability, specificity, and sensitivity, practical DEAs implementation faces challenges such as substrate instability, inefficient aptamer immobilization, and limitations in manufacturing scalability. Future research should prioritize developing moisture-resistant composite substrates, directional aptamer immobilization techniques, and intelligent microfluidic-integrated systems to advance DEAs deployment in multi-field sensing applications.