On-Field Detection of Helicoverpa armigera Nuclear Polyhedrosis Virus Using Luminescent Amphiphilic Probe: Screening of Agricultural Crops and Commercial Formulations

Abstract

An easy to synthesize luminescent, amphiphilic probe has been designed for the first time in optical sensing of a biopesticide, Helicoverpa armigera nuclear polyhedrosis virus (HaNPV). The compound showed formation of a pH-sensitive, thermoreversible nanoaggregate in the aqueous medium. The addition of HaNPV resulted in the rapid change in emission color from blue to cyan at pH 7.4. Till date, no optical assay is known in the literature, which can achieve fast, on-field detection of HaNPV as low as ∼103 POBs/mL. Most importantly, because of naked-eye response, this method does not need the involvement of trained personnel or any sophisticated visualizing instrument. In addition, the distinct optical response also allows us to distinguish the freshly prepared pesticide solution from its storage-old analogue. The quantification of HaNPV is achieved in a wide range of agricultural crop extracts, known to be infected by H. armigera. Inexpensive reusable paper strips are developed for on-location detection purposes. Moreover, the presence of residual HaNPV can also be traced on leaf surfaces. Thus, studies of such kind will be beneficial for quality verification of HaNPV and will surely add a new dimension to the better management of H. armigera and minimize the extent of crop loss.

Switchable Luminescent Probe for Trace-Level Detection of the Spodoptera litura Nuclear Polyhedrosis Virus via a Color-Changing Response

“…28 For this, the SLNPV solution was subjected to heat treatment and characterized according to the reported procedure. 29 The heat-treated SLNPV solution showed a significant change in circular dichroism (CD) spectra as well as luminescence signal compared to those of the fresh sample (Figure S2b,c). This essentially indicates the heat-mediated denaturation of the polyhedron protein layer.…”

“…In addition, it is essential to distinguish “freshly made”, active SLNPV from its relatively ineffective (due to heat and UV irradiation) storage-old formulations for quality control purposes . For this, the SLNPV solution was subjected to heat treatment and characterized according to the reported procedure . The heat-treated SLNPV solution showed a significant change in circular dichroism (CD) spectra as well as luminescence signal compared to those of the fresh sample (Figure S2b,c).…”

Imidazolium-Modified Bispyrene-Based Fluorescent Aggregates for Discrimination of Multiple Anions in Aqueous Solution

“…As illustrated in Figure b and SI Figure S17a,b, in the presence of SO 4 2– and SDS, the quenched excimer emission can gradually recover during the heating process and then decreases along the cooling process. The reversible temperature-dependent fluorescence emission indicates that anions like SO 4 2– and SDS are involved in the assembling process . Quite differently, the sensor mixed with PPi does not show reversible temperature-dependent emission behaviors (SI Figure S17c).…”

“…The reversible temperature-dependent fluorescence emission indicates that anions like SO 4 2− and SDS are involved in the assembling process. 48 Quite differently, the sensor mixed with PPi does not show reversible temperature-dependent emission behaviors (SI Figure S17c). This may be due to the strong electrostatic interaction between the aggregates and PPi bearing four negative charges, which makes the assembling process less dynamic and reversible.…”

Nanomaterials for virus sensing and tracking

“…89,451 Fluorescent probes based on carbazole form thermoreversible nanoassemblies with extraordinary solid-state fluorescence. 452 These probes do not form nanoaggregates in the presence of the target virus due to electrostatic association resulting in an immediate change in color.…”