Viral-templated gold/polypyrrole nanopeapods for an ammonia gas sensor

Abstract

One-dimensional gold/polypyrrole (Au/PPy) nanopeapods were fabricated using a viral template: M13 bacteriophage. The genetically modified filamentous virus displayed gold-binding peptides along its length, allowing selective attachment of gold nanoparticles (Au NPs) under ambient conditions. A PPy shell was electropolymerized on the viral-templated Au NP chains forming nanopeapod structures. The PPy shell morphology and thickness were controlled through electrodeposition potential and time, resulting in an ultra-thin conductive polymer shell of 17.4 ± 3.3 nm. A post-electrodeposition acid treatment was used to modify the electrical properties of these hybrid materials. The electrical resistance of the nanopeapods was monitored at each assembly step. Chemiresistive ammonia (NH3) gas sensors were developed from networks of the hybrid Au/PPy nanostructures. Room temperature sensing performance was evaluated from 5 to 50 ppmv and a mixture of reversible and irreversible chemiresistive behavior was observed. A sensitivity of 0.30%/ppmv was found for NH3 concentrations of 10 ppmv or less, and a lowest detection limit (LDL) of 0.007 ppmv was calculated. Furthermore, acid-treated devices exhibited an enhanced sensitivity of 1.26%/ppmv within the same concentration range and a calculated LDL of 0.005 ppmv.

Conducting polymer percolation gas sensor on a flexible substrate

“…34 Three notable exceptions are reported in the studies. Yan et al 35 reported an LOD of 0.007 ppm using viral-templated gold/PPy nanopeapods, although the R 0 baseline was never recovered fully after initial exposure. Chartuprayoon et al 36 achieved a LOD of 0.5 ppm using PPy nanoribbons, and Lee et al 37 who report a minimum detectable level (MDL) of 0.01 ppm using urchin-like nanoparticles decorated with iron oxide nanoneedles.…”

Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

“…The significant performance of ammonia sensors was recognized in the work of Yan et al [117]. Compared with the previously described PPy-based sensors, the authors used a special viral-template, based on a genetically modified M13 bacteriophage with a gold-binding peptide.…”

Phage‐Enabled Nanomedicine: From Probes to Therapeutics in Precision Medicine

“…Self-assembled phage–gold networks have even been used to create other types of nanomaterials, including sensors for hydrogen sulfide [63] and ammonia gas. [64] Additionally, Capehart et al have demonstrated that MS2 phage capsids can be assembled around gold nanoparticles to form a metal-enhanced fluorophore. [53b The resulting metal-enhanced fluorophore can serve as an imaging agent.…”