Gold nanoprism/Tollens’ reagent complex as plasmonic sensor in headspace single-drop microextraction for colorimetric detection of formaldehyde in food samples using smartphone readout

Silver-doped hydroxyapatite for formaldehyde determination by digital-image colorimetry

“…16,18–20,40–42 The sensitivity of both optical spectroscopic methods and digital-image colorimetry could be improved by separating formaldehyde from the sample matrix and performing the reaction in a confined surface as shown in the application of fluorescein on PVA film 15 and headspace single drop microextraction. 21,42 In addition, the detection of trace formaldehyde by digital-image colorimetry would require a highly sensitive reaction as demonstrated in the application of Tollens' reagent modified with gold nanoprisms used in headspace single drop microextraction. 21 Herein, the determination of trace formaldehyde was achieved by the Tollens' reaction on the material surface without using additional nanoparticles.…”

“…21,42 In addition, the detection of trace formaldehyde by digital-image colorimetry would require a highly sensitive reaction as demonstrated in the application of Tollens' reagent modified with gold nanoprisms used in headspace single drop microextraction. 21 Herein, the determination of trace formaldehyde was achieved by the Tollens' reaction on the material surface without using additional nanoparticles. Application of high-volume samples also contributed to the high method sensitivity.…”

“…Regardless of the simplicity, the methods were not sensitive enough for trace level formaldehyde detection. Qi and co-workers 21 proposed a highly sensitive method based on the head space single drop-microextraction of formaldehyde gas released from a sample solution coupled with the quantification using a gold nanoprism/Tollens' reagent complex (Au-np/TR). The reaction of formaldehyde with silver ions in the Au-np/TR yielded a coating of elemental silver on the gold nanoparticles with an ensuing color change of the droplet.…”

Fluorescence Sensing of Formaldehyde and Acetaldehyde Based on Responsive Inverse Opal Photonic Crystals: A Multiple-Application Detection Platform

“…Up to now, besides the common chromatographic and spectrum techniques including gas chromatography–mass spectrometry, high-performance liquid chromatography, and surface-enhanced resonance Raman scattering, many different detection techniques based on various materials have been extensively developed, such as the quartz crystal microbalance method based on polydopamine nanotubes, , electrochemical method based on semiconductor oxide nanomaterials , or ionic microchannel constructed from a polymer nanofibrous membrane, colorimetric detection based on Au nanoparticles with Tollen’s reagent, , cellulose nanocrystal thin films or designed chromogenic molecules, and fluorescence (FL) sensing based on fluorescent probes. − In particular, the FL detection method has aroused wide interests because of its simplicity, excellent sensitivity and selectivity, and potential applications in intracellular detection. For example, aggregation-induced emission FL probes based on tetraphenylethene derivatives have been explored to detect gaseous FA with high sensitivity and endogenous and exogenous FA in living cells .…”

Single bubble in‐tube microextraction coupled with capillary electrophoresis

“…For an additional selectivity and preconcentration power, HS extraction using a solid or liquid acceptor phase was developed [3,4]. Over the years, HS extraction has evolved to miniaturized, economic, more efficient, and greener HS-solid phase microextraction (SPME) and HS-liquid phase microextraction [5][6][7][8][9][10]. In most cases, HS-SPME is carried out using an acceptor-coated fiber [11,12] and HS-liquid phase microextraction is done using a single acceptor drop hanging to a syringe needle tip, which is called single drop microextraction (SDME) [13,14].…”