SERS-active Au@Ag core-shell nanorod (Au@AgNR) tags for ultrasensitive bacteria detection and antibiotic-susceptibility testing

• Published in: Talanta (Oxford) 2020-12, Vol.220, p.121397-121397, Article 121397
• Main Authors: Bi, Liyan, Wang, Xiao, Cao, Xiaowei, Liu, Luying, Bai, Congcong, Zheng, Qingyin, Choo, Jaebum, Chen, Lingxin
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antibiotic susceptibility testing; Au@AgNR; Bacteria; Escherichia coli; Gold; Mice; Mice, Inbred C57BL; Minimum inhibitory concentration; Nanotubes; Principal component analysis; SERS nanotag; Silver; Spectrum Analysis, Raman
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2020.121397

There is a challenge to obtain an ultrasensitive and rapid approach to detect bacteria and identify resistance. As a powerful bioanalytical tool, surface-enhanced Raman scattering (SERS) in bacterial detection have attracted increasing attentions. Herein, we developed a SERS-active Au@Ag core-shell nanorod (Au@AgNR) tag platform for ultrasensitive bacteria detection and antibiotic-susceptibility testing (AST). The platform established that surface enhanced Raman scattered Rhodamine 6G (R6G) absorption at 1517 cm−1 had a good linearity (RI = 3865 + 193logC; R2 = 0.97) with logarithm of E. coli concentration over a range of 107–102 CFU (colony forming unit)/mL with limit of detection as low 102 CFU/mL. When E. coli was exposed to ampicillin at minimum inhibitory concentration (MIC, 4 μg/mL), Raman spectroscopy showed the obvious variation between ampicillin-susceptible E. coli (Amp−-E. coli) and the ampicillin-resistant E. coli (Amp+-E. coli). Combined with principal component analysis (PCA) statistical analysis, the Raman intensity variation mentioned above allows to obtain rapid antibiotic resistance testing (