A filter-like AuNPs@MS SERS substrate for Staphylococcus aureus detection.
An accurate, highly sensitive and rapid identification assay of cells is extremely important in areas such as medical diagnosis, biological research, and environmental monitoring. Laboratory examinations of clinical isolates require time-consuming and complex processes to identify the colony count, with approximately 10(6)-10(8) cells needed for the characterization of strains. In the present study, a highly sensitive SERS filter-like substrate is prepared with AuNPs embedded in mesoporous silica (denoted as AuNPs@MS) synthesized by a simple one-spot method, and an example of its use for the filtration and concentration of analytes from aqueous samples is reported. In an application for Staphylococcus aureus SERS discrimination, the results show that the target cells can be concentrated on the filter-like AuNPs@MS substrates within a few seconds, with much better reproducibility with regard to the SERS spectra that are obtained. The experimental findings suggest that the AuNPs@MS substrate supports much higher intensity with more distinguishable peaks compared to Au/Cr-coated substrate, and the reproducibility is also significantly improved. The substrates investigated in this study generated 900 times more SERS signals at a concentration of 10(6)CFU/mL in the detection of S. aureus on mesoporous silica (Au wt%=0) when using AuNPs@MS with 16 wt% AuNPs. The limitation of this filter-like SERS substrate can be applicable for small volume samples (few to hundred microliter).
Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan.
Chi-Chang
CC
Lin
Ying-Mei
YM
Yang
Pei-Han
PH
Liao
Duo-Wen
DW
Chen
Hong-Ping
HP
Lin
Hsien-Chang
HC
Chang
D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification* / Q000472:pathogenicity; D013499:Surface Properties
D006046:Gold; D012822:Silicon Dioxide
Bacteria fingerprint; Mesoporous silica; Nanoparticles; SERS