Hydrogel SERS chip with strong localized surface plasmon resonance for sensitive and rapid detection of T-2 toxin

T-2 toxin is one of the naturally dangerous food contaminants, which is harmful to people and animals. Because of its strong toxicity and wide distribution, it is vital to develop a rapid and effective method for the detection of T-2 toxin. Herein, an excellent hydrogel surface-enhanced Raman scattering (SERS) chip is constructed for developing a novel SERS sensor to detect T-2 toxin using a portable Raman spectrometer. The SERS chip is prepared by in-situ Ca²⁺-mediated assembly of silver nanoparticles (AgNPs) in PVA solution, followed by a physical crosslinking possess. The assembled AgNPs produces a strong localized surface plasmon resonance (LSPR) at around 532 nm, which enables the high activity of SERS chip under the irradiation of 532 nm laser. Additionally, the unique structure of hydrogel makes the obtained chip show excellent reliability and anti-interference ability in detection. As a result, the developed SERS sensor shows many obvious advantageous including free of complex sample pretreatment (only a simple extraction), fast response (5 min), low limit of detection (0.41 ppb), wide detection range (1-10000 ppb), good recoveries (90.26-101.81 %) and relative standard deviations (2.8-6.7 %). Therefore, this SERS sensor provides a promising choice for rapid scanning and sensitive detection of trace T-2 toxin in complex matrices.