|
| Analytical methods for H2S | Cell types | Experimental conditions forH2S production | H2S concentration | Advantages & limitations | Ref. |
|
| Spectrophotometric method | In situ methylene blue assay | Rat A10 cells | 24 h incubation with 1, 3, and 5 mM of Cys and 1, 2, and 5 mM NAC | μM (with 3 mM Cys)
μM (with 2 mM NAC) | (Adv.) cost-effective & adaptable to most lab. settings
(Limit.) low sensitivity, several complex steps & interferences with colored substances | [43] |
| Ag2S@AgNPs in a layer-by-layer film | HepG2 cells | 2 h incubation with Cys and PLP (+Ag amplification for 2 h) | — | (Adv.) high sensitivity (10 nM)
(Limit.) additional amplification time (2 h), except for the reaction time (2 h) | [44] |
| Ag-embedded Nafion/PVP membrane | Rat C6 glioma cells | SAM treatment and with a combination of Cys (10 mM) and hCys (0.5 mM) for 48 h | μM | (Adv.) simple, facile, cost-effective, & adaptable to most lab. settings
(Limit.) low sensitivity & treatment with high levels of substrates | [45] |
| Au/AgI dimeric NPs | HepG2 cells | 24 h incubation with 2 mM of Cys and 0.5 mM PLP | cells | (Adv.) good sensitivity (500 nM)
(Limit.) long response time | [48] |
|
| Fluorescence detection and imaging | Reduction of the azido group ( nm) | HeLa cells | Prestimulation with 100 μM of SNP (NO donor) for 60 min | — | (Adv.) high sensitivity (LOD 5.7 nM)
(Limit.) only fluorescence cell imaging & long response time | [50] |
| Reduction of azide to amine ( nm) | HUVECs | Stimulation with VEGF (40 ng/mL) for 30 min | Intracellular fluorescence ratio
(vs. 1.07 of control) | (Adv.) good sensitivity (LOD 500 nM)
(Limit.) long response time | [52] |
| Nucleophilic cleavage of the ether bond ( nm) | HeLa cells | 1 h incubation with NaHS (100, 200, and 300 μM) | — | (Adv.) good sensitivity (LOD 500 nM)
(Limit.) only fluorescence imaging & long response time | [53] |
| H2S-triggered disassembly of QDs/AgNP complexes ( nm) | HeLa cells | Pretreatment with 300 μM NaHS for 30 min | — | (Adv.) high sensitivity (LOD 15 nM)
(Limit.) only fluorescence imaging & long response time | [54] |
| Reduction of azide to amino group | HeLa cells | 60 min incubation with Na2S (100 μM) | The fluorescence intensity (red, 605 nm)/blue, 525 nm) ratio 2.416 (vs. 1.498 of untreated cells) | (Adv.) enhanced detection accuracy (ratiometric analysis)
(Limit.) long response time | [56] |
|
| Surface-enhanced Raman scattering | Rat C6 glioma cells & human U251 MG glioma cells | SAM stimulation | Ratiometric Raman peak intensity : about 10-fold increase after 2 h stimulation of SAM | (Adv.) good sensitivity (LOD 0.1 μM) & fast response time (1 min)
(Limit.) needs specific SERS probe and expensive instrument | [66] |
|
| Paper-based colorimetric assay | LNCap cells | 72 h incubation with 5 mM of Cys and 1 mM hCys | μM
(72 h) | (Adv.) simple, low-cost, practical, & moderate sensitivity (LOD 1.4 μM)
(Limit.) treatment with high levels of substrates | [73] |
|
| Dual-mode detection | Colorimetry & near-IR fluorescence | MCF-7 cells | 30 min incubation with NaHS (10, 50, and 100 μM) | — | (Adv.) moderate sensitivity (LOD 3.09 μM) & fluorescence “off-on” response
(Limit.) only fluorescence imaging | [77] |
| Colorimetry & fluorescence | NHOF cells | 0, 20, and 60 min incubation with NaHS (10 μM) | — | (Adv.) good sensitivity (LOD 0.17 μM)
(Limit.) only fluorescence imaging | [78] |
| Colorimetry & SERS | LNCap cells | Cys (5 mM) and hCys (1 mM) treatment for 8, 16, and 24 h | μM
(8 h)
μM (16 h)
μM
(24 h) | (Adv.) high sensitivity (LOD 15 nM for SERS detection & LOD 520 nM for colorimetry)
(Limit.) treatment with substrates | [79] |
| Colorimetry & luminescence | HeLa cells | 30 min incubation with H2S (200 μM) | — | (Adv.) high sensitivity (LOD 53.9 nM)
(Limit.) only luminescence imaging | [80] |
|
