Highlights

We introduce a colorimetric and SERS sensor for the dual-mode detection of H₂S.

A simple and facile H₂S assay was prepared by dropping of Ag nanoplate solution on paper.

We utilized the parameter b of CIE L*a*b color model for the quantitative color analysis.

The analytical performance of H₂S sensing paper for dual-mode detection was evaluated.

This paper assay can detect endogenous H₂S in live LNCaP cells under shorter incubation times.

Abstract

We report a simple and facile paper assay based on silver nanoplates (Ag NPls) for the colorimetric and surface-enhanced Raman scattering (SERS) dual-mode detection of hydrogen sulfide (H₂S) gas released from live cancer cells. Ag NPls were prepared via seed-mediated growth and dropped on detection zones within the poly(dimethylsiloxane)-patterned paper substrate. The blue-colored Ag NPls on the paper react with H₂S to form brown-colored silver sulfide, which simultaneously decreases SERS activity of Ag NPls. We quantitatively analyzed the color and Raman signal intensity changes in Ag NPl-coated detection zone on the paper, using the parameter b of L*a*b color space and Raman peak at 1356 cm⁻¹ of Rhodamine B, respectively. As a result, our Ag NPl-coated H₂S dual-sensing paper assay showed a good sensitivity with a linear range of 1.64–16.4 μM H₂S and a detection limit of 520 nM for colorimetric detection. And, it also represented a high sensitivity with a linear range of 82–330 nM H₂S for SERS detection. In addition, it possessed high selectivity, excellent reproducibility, and high stability over 1 month. Using this Ag NPl-coated H₂S dual sensing paper, we successfully measured the H₂S concentration in live prostate cancer cells at different incubation times and cell numbers. Therefore, the Ag NPl-coated paper assay can be utilized as a facile and effective tool for the dual-mode colorimetric and SERS detection of free H₂S gas within live cells without complicated sample processing or labor-intensive bioanalytical methods.