Chia-Ying Liu, Yin-Yi Han, Po-Han Shih*, Wei-Nan Lian, Huai-Hsien Wang, Chi-Hung Lin, Po-Ren Hsueh, Juen-Kai Wang*, Yuh-Lin Wang*
Scientific Reports 6, 23375 (2016).
Rapid bacterial antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) measurement are important to help reduce the widespread misuse of antibiotics and alleviate the growing drug-resistance problem. We discovered that, when a susceptible strain of Staphylococcus aureus or Escherichia coli is exposed to an antibiotic, the intensity of specific biomarkers in its surface-enhanced Raman scattering (SERS) spectra drops evidently in two hours. The discovery has been exploited for rapid AST and MIC determination of methicillin-susceptible S. aureus and wild-type E. coli as well as clinical isolates. The results obtained by this SERS-AST method were consistent with that by the standard incubation-based method, indicating its high potential to supplement or replace existing time-consuming methods and help mitigate the challenge of drug resistance in clinical microbiology.
T. Y. Liu, K. T. Tsai, H. H. Wang, Y. Chen, Y. S. Chen, Y. C. Chao, H. H. Chang, C. H. Lin, J. K. Wang, Y. L. Wang*
Nat. Commun., 2, 538 (2011)
Detecting bacteria in clinical samples without using time-consuming culture processes would allow rapid diagnoses. Such a culture-free detection method requires the capture and analysis of bacteria from a body fluid, which are usually of complicated composition. Here we show that coating Ag-nanoparticle arrays with vancomycin (Van) can provide label-free analysis of bacteria via surface-enhanced Raman spectroscopy (SERS), leading to a ~1,000-fold increase in bacteria capture, without introducing significant spectral interference. Bacteria from human blood can be concentrated onto a microscopic Van-coated area while blood cells are excluded. Furthermore, a Van-coated substrate provides distinctly different SERSspectra of Van-susceptible and Van-resistant Enterococcus, indicating its potential use for drug-resistance tests. Our results represent a critical step towards the creation of SERS-based multifunctional biochips for rapid culture- and label-free detection and drug-resistant testing of microorganisms in clinical samples.
N.-W. Liu, A. Datta, C.-Y. Liu, C.-Y. Peng, H.-H. Wang, Y.-L. Wang
Adv. Materials 17, 222-225 (2005)
Focused ion beam (FIB) lithography can be used to selectively close nanochannels in an ordered array on an anodic-alumina film, producing templates with the nanochannels arranged in custom-designed geometries. Nanochannel closing can be monitored by in-situ FIB imaging. Nanodevices such as photonic-crystal waveguides could be fabricated using this technique.
Institute of Atomic and Molecular Sciences Academia Sinica
