Label-Free\nSurface-Enhanced Raman Spectroscopy Biosensor\nfor On-Site Breast Cancer Detection Using Human Tears

Abstract

Surface-enhanced\nRaman scattering (SERS) is an ultrasensitive molecular\nscreening technique with greatly enhanced Raman scattering signals\nfrom trace amounts of analytes near plasmonic nanostructures. However,\nresearch on the development of a sensor that balances signal enhancement,\nreproducibility, and uniformity has not yet been proposed for practical\napplications. In this study, we demonstrate the potential of the practical\napplication for detecting or predicting asymptomatic breast cancer\nfrom human tears using a portable Raman spectrometer with an identification\nalgorithm based on multivariate statistics. This potentiality was\nrealized through the fabrication of a plasmonic SERS substrate equipped\nwith a well-aligned, gold-decorated, hexagonal-close-packed polystyrene\n(Au/HCP-PS) nanosphere monolayer that provided femtomole-scale detection,\ngiga-scale enhancement, and <5% relative standard deviation for\nreliability and reproducibility, regardless of the measuring site.\nOur results can provide a first step toward developing a noninvasive,\nreal-time screening technology for detecting asymptomatic tumors and\npreventing tumor recurrence.