Corrigendum: Contactless and robust dielectric microspheres-assisted surface-enhanced Raman scattering sensitivity improvement for anthrax biomarker detection.

[This corrects the article DOI: 10.3389/fchem.2022.1057241.].

Contactless and robust dielectric microspheres-assisted surface-enhanced Raman scattering sensitivity improvement for anthrax biomarker detection.

This report presents a contactless and robust dielectric microspheres (DMs)-assisted surface enhanced Raman scattering (SERS) enhancement method to improve SERS detection sensitivity detection sensitivity. DMs that could focus and collect light were embedded within the polydimethylsiloxane (PDMS) film to avoid direct contact with the analytical solution and improve detection reliability. The as prepared DMs embedded PDMS (DMs-PDMS) film was integrated with a microfluidic technique to enhance the SERS signal of a liquid substrate. Detection in microfluidic systems can reduce reagent consumption, shorten assay time, and avoid evaporation of the colloid substrate solution. The robustness and potential influencing factors of DMs-PDMS film assisted SERS enhancement (DERS) were evaluated using 4-aminothiophenol (4-ATP) as the Raman probe. The sensing performance of the proposed method toward dipicolinic acid (DPA) was evaluated, and an evident signal intensification was obtained. Remarkably, the DMs-PDMS film can also be implemented on solid substrates. A proof-of-concept experiment was performed by covering the DMs-PDMS film directly over an AgNPs@Si solid substrate wherein a 5.7-fold sensitivity improvement was achieved.

In situ synthesis of low-cost and large-scale flexible metal nanoparticle-polymer composite films as highly sensitive SERS substrates for surface trace analysis.

Surface-enhanced Raman spectroscopy (SERS) has been one of the most promising analytical tools. Despite many efforts in the design of SERS substrates, it remains a great challenge for creating a general flexible substrate that could in situ detect analytes on diverse objects. Herein, we report our attempt to address this issue by developing a facile and versatile method capable of generating silver/gold nanoparticles in situ on the surface of a cellulose acetate (CA) polymer in a simple, cheap, practical, and capping agent-free way. The as-prepared substrates exhibit excellent sensitivity, which enabled detection of Rhodamine 6G at concentrations as low as 10-12 M. Taking advantage of the excellent flexibility and optical transparency of the CA matrix, the highly SERS-active substrate was applied for in situ identification and detection of pesticide residues on fruits. The results indicated that tetramethylthiuram disulfide (TMTD) and thiabendazole (TBZ) can be clearly identified at concentrations as low as 18.05 ng cm-2 and 15.1 ng cm-2, respectively, which were much lower than the maximum permitted residue doses with respect to food safety.

Selective adsorption of Hg(II) by γ-radiation synthesized silica-graft-vinyl imidazole adsorbent.

Silica-based adsorbent was prepared by γ-radiation induced grafting of vinyl imidazole (VIM) onto the silanized silica, which was silanized by chlorotrimethylsilane (TMCS). The effects of monomer concentration and absorbed dose on the grafting yield were investigated to optimize the reaction conditions. Thermodynamic analysis, FTIR analysis and XPS spectra manifested that VIM was successfully grafted onto the silica surface. The SS-g-VIM adsorbent had excellent selectivity for Hg(II) adsorption in mixture divalent cationic metal solution and a high adsorption capacity of Hg(II). The theoretical maximum adsorption capacity was calculated to be 355.9 mg g(-1) (1.774 mmol g(-1)) in HgCl(2)/HNO(3) solution at pH 5 at room temperature. The adsorption kinetics and adsorption isotherm were investigated. It was found that the Langmuir isotherm model fitted well with the adsorption process and the adsorption of Hg(II) onto SS-g-VIM adsorbent could be considered as a spontaneous, endothermic and chemical sorption process. The comprehensive results suggested that SS-g-VIM adsorbent has potential application for the removal of Hg(II) from wastewater.