Detection of explosive compounds using Photosystem II-based biosensor

Abstract

a b s t r a c tThe efficacy of a Photosystem II (PS II)-based biosensor for the detection of explosive compounds has been explored. The idea is based on the close similarities in the chemical structures of the widespread explosives and herbicides, with the latter known to inhibit functioning of the PS II by attaching to the binding site of the Q B mobile plastoquinone electron acceptor. The gold screen-printed electrodes (Au-SPE) functionalized with PS II-enriched particles were used for the detection of explosives in a droplet biosensor configuration. A crude preparation of PS II produced from spinach leaves, known as BBY particles, was employed to modify the Au-SPE working electrode employing BSA-glutaraldehyde-based immobilization procedure. Inhibition of the PS II functioning was detected by photo-electrochemical measurements in the presence of a mediator (either non-native quinone or ferricyanide). The biosensor was highly responsive to herbicides (as expected) as well as to picric acid, with limits of detection in the nanomolar range, but trace detection of trinitrotoluene (TNT) was not effective. The detection limit for picric acid was 25 nM as compared to $400 nM for TNT with duroquinone mediator. Low affinity of PS II to TNT has been corroborated by means of DCPIP assay; possible reasons for low affinity are discussed.

Current trends in explosive detection techniques

“…This disrupts the electron transfer process and decreases the resulting photocurrent, which was observed through steady-state electrochemical interrogation. The detection limit in MES buffer for picric acid in this system was found to be 5.7 μg L -1[89]., reported the combination of electrochemical and piezoelectric transduction mechanisms as a detection technique, using the ionic liquid BMIBF 4…”

High-performance electrochemical amperometric sensors for the sensitive determination of phenyl urea herbicides diuron and fenuron

“…Moreover, DU is also employed in water bodies, home aquaria, fountains, boats, and aquaculture to control algae (algaecide) [2,3]. It blocks the light reaction of photosystem II by selective reversible binding at the quinone binding site which results in complete hindrance of electron transfer from quinone to plastoquinone; as a consequence, photosynthesis was inhibited [4,5]. Due to the widespread usage and high persistence of DU, its residues are likely to be present in water resources such as rivers, lakes, ground water, soils, and crop areas.…”

SingleChlamydomonas reinhardi(C. reinhardtii) cell separation from bacterial cells and auto-fluorescence tracking with a nano-sieve device

“…For example, microalgal biofuel provides a unique solution to the renewable energy problem because microalgae demonstrate many advantages including high growth rate (Wan et al, 2015), similar co-products to conventional fuels after oil extraction (Spolaore et al, 2006), waste-water remediation capability (Cantrell et al, 2008), no need for arable land (Searchinger et al, 2008), and carbon dioxide fixation capabilities (Chisti et al, 2007). Microalgae can perform charge separation and electron transfer processes with sensitivity to heavy metals, pesticides, explosive compounds and volatile organic compounds measured in a variety of manners (Rouillon et al, 2006; Hernandez et al, 2011; Rea et al, 2011; Bhalla et al, 2011; Brayner et al, 2011). This makes photosynthetic microalgae ubiquitous in researching the monitoring of food, agricultural products, and the aquatic environment for hazardous compounds.…”