Molecularly Imprinted Photonic Crystals Based on Fusaric Acid for the Detection of Banana Fusarium Wilt

Abstract

Banana Fusarium wilt is a soil-borne disease caused by Fusarium oxysporum f. sp. cubense (Foc) in which F. oxysporum f. sp. cubense race 4 (Foc4) could infect all kinds of banana and has caused great damage to the banana planting industry. The most important means to prevent and control banana Fusarium wilt in agricultural production is to control the spread and invasion of pathogens. Among them, the detection and determination of banana Fusarium wilt in the field is essential and thus is the basis of protection. Since fusaric acid (FA) is one of the specific products present during the metabolic processing of Fusarium wilt pathogens, by combining FA with molecularly imprinted photonic crystal (MIPC) technologies, a series of MIPCs based on monodispersed silica, FA, and cross-linked polymers, i.e., MIPC-FA, which could be recycled, were designed and prepared. It was found that the responses of MIPC-FA were affected by the cross-linking degree of the polymer matrix and the pH values. The results showed that MIPC-FA could effectively detect FA in a solution of FA in a minute scale, Foc4-containing medium, and banana plants infected by Foc4, and the response was related to the FA concentration, which makes it an effective and fast method to detect and determine banana Fusarium wilt caused by Foc4 in the field.