Dual-Responsive Benzo-Hemicyanine-Based Fluorescent Probe for Detection of Cyanide and Hydrogen Sulfide: Real-Time Application in Identification of Food Spoilage

Abstract

Colorimetric and fluorescent probes have received a lot of attention for detecting lethal analytes in realistic systems and in living things. Herein, a dual-approachable Benzo-hemicyaninebased red-emitting fluorescent probe PBiSMe, for distinct and instantaneous detection of CN– and HS– was synthesized. The PBiSMe emitted red fluorescence (570 nm) can switch to turn-off (570 nm) and blue fluorescence (465 nm) in response to CN– and HS–, respectively. Other nucleophilic reagents, such as reactive sulfur species (RSS) and anions, have no contact or interference with the probe; instead, a unique approach is undertaken to exclusively interact with CN– and HS– over a wide pH range. The measured detection limits for CN– (0.43 μM) and HS– (0.22 μM) ions are lower than the World Health Organization’s (WHO) recommended levels in drinking water. We confirmed 1:1 stoichiometry ratio using Job’s plot and observed good quantum yield for both analytes. The probe-coated paper strips were used to detect the H2S gas produced by food spoilage (such as eggs, raw meat, and fish) via an eye-catching visual response. Moreover, fluorescence bioimaging studies of living cells was done to confirm the probe’s potential by monitoring the presence of CN– and HS– in a living system.

Activity-Based Fluorescent Probes for Hydrogen Sulfide and Related Reactive Sulfur Species

“…Velmathi used a naphthyl indole to generate 726 (PBiSMe), which provided a fluorescence response to H 2 S at 465 nm, although this probe also reacted with but did not provide a fluorescent response for CN − . 736 This probe was also demonstrated to image exogenous H 2 S in HCT-116 cells. As an additional example of sulfur incorporation, Yin reported thiophene conjugated 727 (N-ThA), which provides a response to both H 2 S and changes in viscosity due to changes conjugation and free rotation around the extended chromophore upon H 2 S addition and increased viscosity, respectively.…”

“…Velmathi used a naphthyl indole to generate 726 (PBiSMe), which provided a fluorescence response to H 2 S at 465 nm, although this probe also reacted with but did not provide a fluorescent response for CN – . This probe was also demonstrated to image exogenous H 2 S in HCT-116 cells.…”

Silica Nanoparticle-Based FRET System for Hydrogen Sulfide Detection in Biological and Food Samples

“…It is known that the process of food spoilage can also produce amine gases. According to the methods in the literature, 54 the influence of amine gases on the test strips was as well studied. As shown in Figure S12c−f, the nanoprobe exhibits similar responses to the presence of amine gases.…”

Development of a Water-Soluble Fluorescent Probe Based on Natural Flavylium for Mercury(II) Ion Detection and Clinical Antidote Evaluation

“…To date, several Hg 2+ detection and analysis techniques have been established with high sensitivity to meet the practical requirements, including spectrophotometry, atomic absorption spectroscopy, atomic fluorescence spectroscopy, X-ray absorption spectroscopy, and inductively coupled plasma mass spectrometry . Nevertheless, their limitations in terms of long detection time, complicated operations, and inability to carry out real-time and on-site detection have limited their application. , In contrast, fluorescence sensing technology has rapidly developed in recent decades, offering advantages such as good selectivity, rapid detection, high sensitivity, and real-time detection. − Recently, several small-molecule fluorescent probes for Hg 2+ detection have been constructed based on coordination or irreversible chemical reactions. For example, Hyung-il Lee et al developed a “turn-on” fluorescent probe based on the dye BODIPY for the detection of Hg 2+ .…”