Scheme 1From: A pump-free and high-throughput microfluidic chip for highly sensitive SERS assay of gastric cancer-related circulating tumor DNA via a cascade signal amplification strategySchematic diagram of the pump-free, high-throughput microfluidic chip-based SERS assay for PIK3CA E542K and TP53. Structural mechanism of A CHA and B HCR. C Preparation of SERS probes and D detection of PIK3CA and TP53Back to article page