Development of an ultrasensitive electrochemical biosensor for detection of Agrobacterium tumefaciens in Rosa hybrida L.

Abstract

Crown gall is one of the destructive diseases of Rosa hybrida L. caused by Agrobacterium tumefaciens. Development of galls leads to an overall weakness, reduction in foliage, water stress, and loss of vigor of the infected plants. We have designed an electrochemical DNA-based biosensor for T-DNA detection. Pencil graphite electrode (PGE) was modified with a nanocomposite including reduced graphene oxide (RGO) and Au nanoparticles. The biosensor sensing element consists of a single-stranded DNA (ss-DNA) from the tms2 gene which binds to thiol gold nanoparticles (GNPs). Under the optimal experiments, the proposed biosensor displayed a wide linear range from 1.0 × 10−13 to 1.0 × 10−9 M with a limit of detection (LOD) of 0.87 × 10−13 M towards target DNA. Experimental analysis on real samples confirmed its application. The proposed biosensor showed an easy and quick detection with high efficiency which was specific to T-DNA contamination of A. tumefaciens, and exhibited high reproducibility and stability.