An octahedral Cu₂O@AgNCs substrate in liquid-microextraction coupled chemometric algorithms for SERS sensing of chromium(iii & vi) species

Abstract

The current study assembles liquid-microextraction, surface enhanced Raman scattering (SERS) and chemometrics algorithms in one platform for chromium speciation using octahedral Cu2O@Ag nanocomposites (Cu2O@AgNCs) as a SERS substrate.

Simultaneously intensified plasmonic and charge transfer effects in surface enhanced Raman scattering sensors using an MXene-blanketed Au nanoparticle assembly

“…For this, there have been several attempts to develop highly sensitive sensors for Cr(VI) detection. 41,42 Particularly, SERS-based sensing has proved exceptionally benecial in detecting and quantitatively estimating low concentrations of Cr(VI) (the lowest detectable limit of 28 ng L À1 of Cr(VI) was reported). 42 In addition, SERS-based sensing is advantageous for detecting Cr(VI) when compared to other methods such as uorescence-based spectroscopy, because it is highly stable against photodegradation or photobleaching.…”

“…41,42 Particularly, SERS-based sensing has proved exceptionally benecial in detecting and quantitatively estimating low concentrations of Cr(VI) (the lowest detectable limit of 28 ng L À1 of Cr(VI) was reported). 42 In addition, SERS-based sensing is advantageous for detecting Cr(VI) when compared to other methods such as uorescence-based spectroscopy, because it is highly stable against photodegradation or photobleaching. 43 For the detection of Cr(VI) with the fabricated SERS platform, we employed the labeling molecule RhB, which works as a messenger delivering quantitative information on the concentration of Cr(VI) (refer to the detailed experimental procedure in Fig.…”

“…5c, the DL of the bilayered SERS substrate presented in this work is signicantly lower than the WHO regulation level (i.e. 1 mg L À1 of Cr(VI) in drinking water), and is also superior to those of other Cr(VI)-detecting Raman sensors reported elsewhere, such as using urchin-like hollow TiO 2 @Ag nanoparticles with a DL of 75 ng L À1 (1.45 nM), 49 octahedral Cu 2 O@Ag nanocomposites with a DL of 28 ng L À1 (0.54 nM), 42 or nanoower-shaped Ag nanoparticles with a DL of 30 ng L À1 (0.58 nM). 45 Furthermore, spike recovery tests were also carried out to assess any possible interfering effects of the sample matrix on the accurate detection of Cr(VI) concentration that might be exerted by various undened species co-present with Cr(VI).…”

“…This concentration range detectable is wider than those from other SERS platforms (i.e., from 100 ng L À1 to 1 mg L À1 ). 42 More importantly, the lowest DL of Cr(VI) was estimated to be 13 ng L À1 , which was determined by the lowest signal-to-noise (S/N) ratio of 3 (Fig. 5b).…”

Insights into chemometric algorithms for quality attributes and hazards detection in foodstuffs using Raman/surface enhanced Raman spectroscopy

“…Moreover, other inherit advantages of Raman and SERS are convenience, lower consumption of reagents, portability, and no requirement of a pretreatment step. The discretionary choice of a pretreatment step makes it a time effective strategy (Ahmad et al., 2019).…”