"Magnet" Based on Activated Silver Nanoparticles Adsorbed Bacteria to Predict Refractory Apical Periodontitis Via Surface-Enhanced Raman Scattering.

Refractory apical periodontitis (RAP) is an endodontic apical inflammatory disease caused by (). Bacterial detection using surface-enhanced Raman scattering (SERS) technology is a hot research topic, but the specific and direct detection of oral bacteria is a challenge, especially in real clinical samples. In this paper, we develop a novel SERS-based green platform for label-free detection of oral bacteria. The platform was built on silver nanoparticles with a two-step enhancement way using NaBH and sodium (Na) to form "hot spots," which resulted in an enhanced SERS fingerprint of with fast, quantitative, lower-limit, reproducibility, and stability. In combination with machine learning, four different oral bacteria (, , and ) could be intelligently distinguished. The unlabeled detection method emphasized the specificity of in simulated saliva, serum, and even real samples from patients with clinical root periapical disease. In addition, the assay has been shown to be environmentally friendly and without secondary contamination through antimicrobial assays. The proposed label-free, rapid, safe, and green SERS detection strategy for oral bacteria provided an innovative solution for the early diagnosis and prevention of RAP and other perioral diseases.