Polydimethylsiloxane microfluidic aptasensor： opening a new era of biomarker point-of-care testing

Microfluidic technology， an emerging micro-nano technology， facilitates the precise manipulation of trace liquids via diverse microstructures. It is distinguished by its miniaturization and cost-effectiveness. Among the synthetic materials employed for microfluidic chips， polydimethylsiloxane （PDMS）， a polymer material， has emerged as the optimal choice for fabricating microfluidic chips. This preference stems from its straightforward manufacturing process， high transparency， outstanding chemical stability， and biocompatibility. Biosensors developed by integrating aptamers， which serve as specific biological receptors， into PDMS microfluidic chips are termed PDMS microfluidic aptasensors. These aptasensors capitalize on the distinctive advantages of aptamers as biological recognition elements in conjunction with microfluidic technology. Microfluidic technology transforms the interactions between biomolecules into readable signals that are readily processed and reported， thereby offering sensing methods characterized by high specificity and sensitivity. This advancement significantly propels the development of point-of-care testing （POCT） for biomarkers， enabling extensive applications in areas such as cancer screening and pathogen detection， and achieving rapid， accurate， and portable testing. The attributes of PDMS microfluidic aptasensors encompass low cost， minimal consumption， short processing time， and disposability. These features effectively curtail the consumption of samples and reagents and shorten the testing duration in the POCT realm. Moreover， optimizing microchannel designs， aptamer immobilization methods， and signal amplification strategies can further enhance the performance of PDMS microfluidic aptasensors and expand their detection range. This paper elaborately expounds on the definition and development of microfluidic technology， the application research of PDMS materials and their preparation processes in microfluidic chip manufacturing， as well as the development and processing of PDMS microfluidic aptasensors. It also enumerates the applications of optical， electrochemical， and dual-mode PDMS microfluidic aptasensors based on dual detection modes in the field of biomarker POCT， thus providing theoretical support for the future development and application of novel microfluidic aptasensors.