Bimetallic-satellite enhanced SERS reporter integrated with CRISPR-Cas12a for ultrasensitive biological rhythm monitoring

Background Biorhythmic played an important role in physical health. Biorhythmic disorders led to various health issue, including cardiovascular diseases and metabolic disorders. Early diagnosis of biorhythmic disorders was crucial in slowing the progression of disease. Therefore, it was important to develop technologies for detecting biorhythmic and their disorder markers. This study selected HMGB1(High mobility group box 1), BMAL1 (Brain and Muscle Aryl hydrocarbon receptor nuclear translocator-like 1), and MICU (mitochondrial calcium uptake 1) mRNA for detection. Results CRISPR/Cas12a/SERS (surface-enhanced Raman spectroscopy) ultrasensitive biosensing platform was developed for the detection of biorhythmic markers. The biosensor was partly an ultrabright Raman signal reporter (on) of a novel satellite structure formed by gold/silver bimetallic nanoparticles. This novel satellite structure utilizes the potential difference between gold and silver nanoparticles to promote the transfer of electrons from the core structure to the AuNPs and MBA (4-mercaptobenzoic acid) molecules, while enhancing the electromagnetic field distribution. Compared with the Raman signal of the satellite structure composed of Au/Au bimetallic, the Raman signal of the satellite structure in this study is increased by about 10 times. CRISPR/Cas12a recognized the target molecule and activated trans -cleavage activity, cleaving the DNA/RNA hairpin structure and releasing RNA 2∗ . RNA 2∗ caused the satellite structure to disperse, significantly attenuating the ultra-strong Raman signal (off), thereby enabling quantitative detection of the target nucleic acid. The LOD for three targets were of less than 1 fM. Significance In summary, the CRISPR/Cas12a/SERS biosensing platform enables mRNA detection without preamplification. This biosensing platform can detect target molecules at the fM level, achieving ultra-sensitive detection. In addition, the satellite structure exhibits long-term stability, providing a theoretical basis for the practical application of this biosensing platform.