A dual-mode colorimetric and SERS detection of hydrogen sulfide in live prostate cancer cells using a silver nanoplate-coated paper assay

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.