Flexible ag-SiO microsphere SERS substrate integrated microfluidic Chip for fungal pathogen detection in rapeseed crop.

Rapeseed Sclerotinia stem rot, caused by Sclerotinia fungi, is a devastating agricultural disease-causing massive yield losses globally. However, the current rapeseed Sclerotinia stem rot detection and control using Raman spectroscopy is limited, and unable to meet the demand for high-precision detection and integration of various types of Sclerotinia stem rot fungus. In this study, a flexible 3D core-shell Ag-SiO microsphere SERS substrate integrated with a pumpless multichannel microfluidic chip was proposed. The flexible SERS substrates were used for precise identification fungus such as Sclerotinia sclerotiorum and Sclerotinia minor. The flexible Ag-SiO microsphere SERS substrate demonstrated a linear detection range of 10-10 M for Rhodamine 6G (R = 0.958), achieving an enhancement factor of 8.5 × 10 at 1506 cm with 6.93 % RSD and 10 M detection limit. The proposed flexible SERS microfluidic chip provides a promising application for microbial detection and analysis.