High-sensitivity qPCR detection method based on silver flower-like LSPR-active material

Quantitative polymerase chain reaction (qPCR) technology offers advantages such as easy operation and high specificity, but also faces issues like lengthy detection time and low sensitivity. This paper proposes a method by using novel SERS-active silver flower-like material to enhance the fluorescence signal generated by qPCR instrument, so as to shorten the detection time and improve the detection sensitivity. In this method, silver flower-like material is first prepared on substrates using a lyotropic liquid crystal soft template combined with electrodeposition growth. Then, an ultrasonic device is used to peel the active material into aqueous solution, and the peeling efficiency reaches 90%. Using rhodamine 6G (R6G) as the qPCR amplification detection molecule, the fluorescence signal generated from the flower-like material-containing sample is increased by 20%. Finally, the qPCR amplification effect is detected with the commercially available new coronavirus nucleic acid detection kit. The results showed that the CT value decreased from 35 to 31 after adding the silver flower-like material, and the detection efficiency increased by 20%. Meanwhile, no non-specific amplification is observed. For COVID-19 samples at S7 concentration, the positive detection rate rises from 1/200 to 2/3 by our method.