Evaporation-Generated Dense Hotspots on Superwettable Patterned Microchips for Multiplex SERS Detection of Acute Myocardial Infarction-Specific miRNAs

Acute myocardial infarction (AMI) poses a threat to human health, and current clinical diagnostic methods cannot achieve early warning of AMI. The accurate detection of AMI-specific miRNAs is of great significance for the early diagnosis and treatment of AMI. However, the low abundance of miRNAs poses a major challenge to the sensitive detection of ultratrace miRNAs. Herein, a superwettable SERS microchip with an evaporation-induced SERS enhancement effect was developed for AMI-specific miRNA detection, which integrated a superwettable patterned surface and DNA walker strategy. Benefiting from the extreme difference in wettability between the superhydrophilic microwell and superhydrophobic background, both target and SERS tag can be sufficiently enriched in the superhydrophilic microwell. Abundant hotspots are generated through a simple evaporation-induced concentration and aggregation, leading to highly responsive and reproducible SERS signals. Coupled with the DNA walker strategy for signal amplification, the prepared superwettable SERS microchip enables the sensitive and multiplexed detection of AMI-specific miRNAs in both buffer and whole serum without interference. Furthermore, the fabricated microchip demonstrates accurate quantification of AMI-specific miRNAs in clinical samples, enabling differentiation among AMI patients, non-AMI individuals presenting with chest pain, and healthy individuals. This advancement provides a facile approach for the accurate diagnosis and early warning of AMI. We envision that this work will open new avenues for the fabrication of SERS biosensors and hold promise for medical diagnostics.