Polyethylene imine-modified photonic crystal microfluidic chip for highly sensitive detection of microbial spores

To address the lengthy cycles, complex operations, high costs, and insufficient sensitivity of biomarker detection in traditional biological control agents, photonic crystal treated with PEI was developed for highly sensitive detection of Sclerotinia sclerotiorum microbial spores. By incorporating gelatin molecules, photonic crystal is endowed with excellent photothermal stability and high stability in aqueous solutions. The photonic crystal surface is conferred a positive charge by PEI, which can be used to enhance the adsorption of spores. Efficient enrichment of Sclerotinia sclerotiorum and Purpureocillium lilacinum spores is achieved, with coefficients of determination 0.963 and 0.971, respectively. The detection range is from 10² to 10⁶ spores/ml, and the photonic crystal exhibited good reusability. The prepared photonic crystal enables rapid, non-destructive, and accurate quantitative detection of microbial spores.