Detection of Pyocyanin Using a New Biodegradable SERS Biosensor Fabricated Using Gold Coated Zein Nanostructures Further Decorated with Gold Nanoparticles

Abstract

In this paper, a biodegradable gold coated zein film surface enhanced Raman spectroscopy (SERS) platform, with gold nanoparticles (AuNPs) deposited on the surface to further enhance the Raman signal, was used to detect pyocyanin (PYO), the toxin secreted by Pseudomonas aeruginosa. An inverted pyramid structure imprinted on a zein film and gold coated during the transfer process was further improved with the deposition and fixing of gold nanoparticles, which resulted in enhancement of the SERS signal by approximately a decade. This new platform served as a lab-on-a-chip sensor to enable the sensitive and rapid detection of PYO in drinking water. The size, distribution, and morphology of the zein film nanostructures including the presence and distribution of gold nanoparticles were characterized by scanning electron microscopy (SEM). The new zein-based platform has the advantage of being largely biodegradable compared with commercial silicon- or glass-based platforms. The limit of detection for PYO using the newly developed zein-based SERS sensor platform was calculated as 25 μM, considerably lower than the concentration of PYO in the blood of people with cystic fibrosis which has been reported to be 70 μM.

DNA‐Origami‐Based Assembly of Au@Ag Nanostar Dimer Nanoantennas for Label‐Free Sensing of Pyocyanin

“…Recently, Jia et al. developed a biodegradable SERS platform using Au‐coated zein film decorated with AuNPs and were able to achieve detection limit in micromolar range [54] . Nam et al.…”

A disposable ultrasensitive surface enhanced Raman spectroscopy biosensor platform fabricated from biodegradable zein nanofibers

“…Surface enhanced Raman spectroscopy (SERS) enables highly sensitive detection of various Raman sensitive analytes that are important for food safety, agriculture, or environmental pollution. [1][2][3][4][5][6] Raman scattering for target molecules in the vicinity of nanostructured noble metals can be enhanced by as much as 10 to 11 orders of magnitude. [7][8][9][10][11] Noble metal nanoparticles of different chemistry and geometry/morphology have been used in SERS measurements for the sensitive detection of biological analytes.…”

In Situ Electrodeposition of Gold Nanostructures in 3D Ultra‐Thin Hydrogel Skins for Direct Molecular Detection in Complex Mixtures with High Sensitivity

“…When the pyocyanin was dissolved at a concentration of 10 n m in a solution containing 0.1 m NaCl and 3 m m HAuCl 4 , strong characteristic peaks of pyocyanin were observed at 840, 1185, 1240, 1294, 1315, 1403, 1459, 1496, 1513, 1567, and 1597 cm −1 after HAuCl 4 reduction at +0.3 V (blue spectra in Figure ); the assignment of the peaks to molecular vibrations is summarized in Table S1, Supporting Information. [ 37–40 ] Notably, the hydrogel‐encapsulated array showed 1.4 times more intense signals than the hydrogel‐free array. However, when pyocyanin was added to the solution after the Au electrodeposition, the characteristic Raman signal intensity was reduced fourfold compared with that measured during in situ Au electrodeposition in the presence of pyocyanin.…”

“…The LOD is 0.012 n m , which is superior to the LODs of other methods based on SERS or electrochemical analysis, as summarized in Table S2, Supporting Information. [ 39–48 ]…”

“…The LOD is 0.012 nm, which is superior to the LODs of other methods based on SERS or electrochemical analysis, as summarized in Table S2, Supporting Information. [39][40][41][42][43][44][45][46][47][48] To further study the influence of the hydrogel on the sensitivity, we acquired Raman spectra of the hydrogel-free nanopillar array while maintaining the same conditions used for in situ nanopillar array formation. The characteristic peaks for the pyocyanin were barely observable at 0.05 nm but recognizable at pyocyanin concentrations of 0.1 nm or greater, and no peaks were detected at concentrations of 0.01 nm or lower (Figure S7, Supporting Information).…”