Smartphone Nanocolorimetric Determination of Hydrogen Sulfide in Biosamples after Silver–Gold Core–Shell Nanoprism-Based Headspace Single-Drop Microextraction

Abstract

In this work, the sensitive detection of hydrogen sulfide (H2S) was realized at low cost and high efficiency through the application of silver–gold core–shell nanoprism (Ag@Au-np) combined with headspace single-drop microextraction (HS-SDME). After SDME, smartphone nanocolorimetry (SNC), with the aid of a smartphone camera and color picker software, was used to detect and quantify the H2S. The method took advantage of the inhibition of the ultraviolet–visible (UV–vis) signal caused by H2S etching of the Ag@Au-np preadded to the SDME solvent to measure the H2S concentration. The coating of the gold layer not only ensured the high stability of the nanomaterial but also enhanced the selectivity toward H2S. The HS-SDME method was simple to process and required only a droplet of solvent for analysis to be realized. This HS-SDME-SCN approach exhibited a calibration graph linearity of between 0.1 and 100 μM and a limit of detection of 65 nM (relative standard deviations of N% (n = 3) < 4.80). A comparison with UV–vis spectrophotometry was conducted. The practical applicability of HS-SDME-SNC was successfully demonstrated by determining H2S in genuine biosamples (egg and milk).

Distance-Based Paper Device Combined with Headspace Extraction for Determination of Cyanide

“…However, they had never been reported for the determination of cyanide. Moreover, paper-based headspace extraction has been developed to enhance the sensitivity and selectivity for sulfite [21], sulfur dioxide [22], volatile organic compounds [23], hydrogen sulfide [24], arsenic [25], and zinc [26] determination. Cyanide will exist as HCN at more acidic than pH 5 so paper-based headspace extraction can be applied for the highly sensitive and selective determination of cyanide.…”

Versatile Graphene‐Isolated AuAg‐Nanocrystal for Multiphase Analysis and Multimodal Cellular Raman Imaging†

“…[ 20‐23 ] Actually, Ag NCs possess larger optical absorption cross section and lower price than Au NCs, [ 24‐25 ] which endows the Ag NCs with greater potential for SERS bioanalysis theoretically. Nevertheless, Ag NCs are easily oxidized in O 2 or H 2 S‐contained environments [ 26‐27 ] and possess potential biotoxicity, [ 28‐29 ] and unnecessary chemical reactions may occur under laser excitation due to the direct contact between probe molecules and Ag NCs, [ 24 ] which severely hinders the SERS biological applications. Hence, it is highly non‐trivial to confine Ag NCs in a stable nanospace for protecting them from complex environments, and meanwhile, avoiding the direct contact with analytes.…”

Biosafety materials: an emerging new research direction of materials science from the COVID-19 outbreak

“…Tang et al prepared an Ag@Au coreshell nanoprobe combined with headspace single-drop microextraction (HS-SDME). 204 Smartphone nanocolorimetry with the aid of a smartphone camera and color picker software was applied to detect and quantify H 2 S (Fig. 17).…”