Detection of benzalkonium chloride on glass surfaces using silver nanoparticles

Abstract

Raman reporter‐based surface‐enhanced Raman scattering (SERS) has been used to investigate the detection of one member of a class of the cationic surfactant quaternary ammonium compounds, alkyl dimethyl benzyl ammonium chloride, also known as benzalkonium chloride (BAC). For this study, SERS was performed using silver nanoparticles (AgNPs). Density functional theory (DFT) of BAC on Ag6 clusters was introduced to estimate binding at the level of the B3LYP/LANL2DZ basis sets. As the chain length increased from n = 8 to 18, the binding energies were expected to increase by 2.1 kcal/mol. Methylene blue (MB) Raman reporter molecules were subsequently treated on BAC thin‐film‐covered glass surfaces. Atomic force microscopy (AFM) images were used to determine the coverage of BAC on the glass, and field‐emission electron microscope (FE‐SEM) images revealed the surface morphologies of the SERS substrates. A standard calibration curve was prepared to quantify BAC within a concentration range of 0.0036805 to 36 805 ppm (r2 ≥ 0.99), according to the BAC‐correlated SERS intensities of MB Raman peaks at ~1620 cm−1 adsorbed on AgNPs. A molecular dynamics (MD) simulation supported strong adsorption of BAC on glass surfaces.

Can DFT Calculations Provide Useful Information for SERS Applications?

“…The DFT approach is increasingly used for SERS spectroscopy by several research groups, as demonstrated by the most recent studies [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ] in which close links between DFT calculations and SERS applications are shown. Among these studies, the following studies devoted to applications in sensors, especially for environmental protection, and to applications in biomedicine, are worthy of particular attention.…”

“…However, because BAC potentially poses risks for human and environmental safety, it is necessary to know the benefits versus the risks of a very extensive use of BAC use in commercial products. Hence, in this paper [ 59 ], an efficient and sensitive SERS method to rapidly detect BAC adsorbed on glass surfaces was employed by using AgNP nanostructures. In this regard, DFT calculations lent valid support to the SERS technique for detecting very low amounts of BAC along with providing significant information on the properties of BAC and its adsorption on metal.…”

Nanoplasmonic assay platforms for reproducible SERS detection of Alzheimer's disease biomarker

“…[13][14][15] To achieve this goal, however, it is crucial to fabricate nanostructures that are capable of forming controllable nanogaps since the electromagnetic enhancement of the incident light is achieved using hot spots created in nanogaps of less than 10 nm diameter. [16][17][18] Recently, tau-381 was detected with high sensitivity via plasmonic coupling effects using the aggregation of gold nanoparticles (AuNPs). 19 However, as described in detail later in this text, the reproducibility is poor in the case of AuNPs aggregated by electrostatic interactions because the nanogaps between the AuNPs cannot be controlled uniformly.…”