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 PD MS 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.

Automated summary

This study presents a contactless and robust dielectric microspheres (DMs)-assisted surface enhanced Raman scattering (SERS) method to improve the sensitivity of SERS detection. The method utilizes DMs embedded within a polydimethylsiloxane (PDMS) film to focus and collect light, avoiding direct contact with the analytical solution and enhancing detection reliability. By integrating the DMs embedded PDMS film with microfluidic techniques, the SERS signal of a liquid substrate is enhanced, reducing reagent consumption and assay time while preventing evaporation. The method was evaluated using 4-aminothiophenol (4-ATP) as the Raman probe and showed significant signal intensification. Moreover, the DMs PDMS film can also be applied on solid substrates, as demonstrated by a proof-of-concept experiment with a 5.7-fold sensitivity improvement on an AgNPs@Si solid substrate.