Detection of Formaldehyde by Surface-Enhanced Raman Spectroscopy Based on PbBiO₂Br/Au₄Ag₄ Nanospheres

Abstract

In this work, a portable surface-enhanced Raman spectroscopy (SERS) substrate based on perovskite-like PbBiO 2 Br/AuAg hybrid nanoalloys (PbBiO 2 Br/Au 4 Ag 4 nanospheres) was fabricated for the rapid, sensitive, and selective detection of formaldehyde. PbBiO 2 Br nanospheres with thin nanosheets on the surface of the microsphere structure were synthesized via the hydrothermal method. The formation of nanospheres was controlled by an ionic liquid ([C 16 mim] + ). [C 16 mim] + can be simultaneously used as a solvent, reactant, and template for fabricating a porous microstructure of PbBiO 2 Br nanospheres. AuAg nanoalloys were grown on PbBiO 2 Br nanospheres in situ in the presence of Au 3+ and Ag + . SERS performance was further optimized by adjusting the ratio of Au/Ag. PbBiO 2 Br/Au 4 Ag 4 membranes as the SERS substrate were further obtained via simple filtration of the PbBiO 2 Br/Au 4 Ag 4 nanospheres on filter paper. The PbBiO 2 Br/Au 4 Ag 4 membranes displayed better SERS activity for molecules with an −SH group than for molecules with nonsulfhydryl targets owing to the high affinity between AuAg nanoalloys and −SH. Under optimum conditions, the method developed herein determined that the analytical enhancement factor of 4-mercaptobenzoic acid and 4-nitrothiophenol could reach 4.5 × 10 8 and 3.2 × 10 7 , respectively. The proposed strategy showed a wide linear range (20.0−500.0 μg L −1 ) and a low limit of detection (2.6 μg L −1 ) for formaldehyde determination. The membrane-based substrate developed in this study offers a novel strategy for fabricating portable and reliable SERS substrates and provides a valid SERS method for rapid on-site monitoring of formaldehyde.

Face-to-Face Assembly of Ag Nanoplates on Filter Papers for Pesticide Detection by Surface-Enhanced Raman Spectroscopy

“…As a common toxic chemical substance, thiram is widely used in plant pest control [48], and thus it is selected as the probe molecule for residual detection in this study. More precisely, we have used the fabricated paper-based SERS substrates for the measurement of thiram in the food safety.…”

Formaldehyde Sensing Using Tapered U-Shape Plastic Optical Fiber Coated With Zinc Oxide Nanorods

“…Several formaldehyde detection methods have been proposed and demonstrated in the previous studies, including cataluminescence [9], spectroscopy [10], bio-sniffer [11], and chemiresistor [12]. However, some of the methods utilized need high temperatures to work, which uses more electricity.…”

A novel signal-on fluorometric sensor based on metal ion-mediated carbon dots for formaldehyde determination and lysosome-targeted bioimaging

“…9 Ultraviolet-visible (UV-vis) spectroscopy and fluorescence (FL) spectroscopy are suitable for the rapid and real-time testing of organic molecules or metal ions. 10,11 With the flourishing development of nanomaterials with FL properties, fluorometric methods are increasingly used in the determination of organic molecules and metal ions. Semiconductor quantum dots (SQDs) and noble metal nanoparticles with outstanding FL performance have advantages in their optical and electrical properties over organic dyes.…”