Leveraging coffee‐ring effect on plasmonic paper substrate for sensitive analyte detection using Raman spectroscopy

Abstract

Raman spectroscopy has demonstrated immense promise as a molecular fingerprinting tool in biomedical diagnostics. However, the utility of conventional Raman scattering for ultrasensitive measurements of biofluids is limited by intrinsically weak signals and has spurred advances in and wider applications of plasmon‐enhanced measurements. Here, we propose a label‐free methodology that leverages drop coating deposition on a silver ink‐based plasmonic paper substrate with tunable hydrophobic attributes to combine two distinct sources of enhancement, namely, solute preconcentration and excitation of localized surface plasmons. The facile modulation of the hydrophobicity of the plasmonic silver paper facilitates investigations into the coffee‐ring effect that results from the interplay of contact line pinning, solvent evaporation, and capillary flow. We show that the Raman spectra acquired from the hydrated ring deposits show clear enhancement beyond that obtained from surface‐enhancement owing to the presence of the silver nanofilm. In light of the superior sensitivity and lack of substantive sample preparation requirements, our findings open the door for a complementary low‐cost paper‐based analytical device for molecular sensing.

Label‐free diagnosis for colorectal cancer through coffee ring‐assisted surface‐enhanced Raman spectroscopy on blood serum

“…The detection region a is the best position for SERS sampling because of two major factors that are both governed by coffee ring effect. One factor is the simultaneous accumulation of nanoparticle at the air‐water interface in the retreating liquid front . The inherit tendency of agglomeration of nanosized particles creates more vacancy that localize the electromagnetic field and generate electromagnetic hot‐spots .…”

Rapid, Label‐free Optical Spectroscopy Platform for Diagnosis of Heparin‐Induced Thrombocytopenia

“…Specifically, we employed a solution‐processed, in situ reduction route to generate the plasmonic coating. The liquid Ag‐ink precursor is drawn in by capillary action, and subsequently heated to form uniform Ag films . The shape of the capillary tube and dilution of the Ag ink form the key parameters in determining the thickness of the Ag film.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

“…Hagiwara and co‐workers combined hot band and Stokes and anti‐Stokes Raman scattering as CO 2 Raman thermometers as an improved Raman thermometer for this molecule . Huang and co‐workers carried out leveraging the coffee ring effect on plasmonic paper substrate for sensitive analyte detection using Raman spectroscopy . Ling and co‐workers carried out a direct observation of 4‐nitrophenyl disulfide produced from p‐nitrothiophenol in air by Raman spectroscopy .…”

“…[201] Huang and co-workers carried out leveraging the coffee ring effect on plasmonic paper substrate for sensitive analyte detection using Raman spectroscopy. [202] Ling and co-workers carried out a direct observation of 4-nitrophenyl disulfide produced from pnitrothiophenol in air by Raman spectroscopy. [203] Maiwald and colleagues described a rapid and adjustable shifted excitation Raman difference spectroscopy (SERDS) using a dual-wavelength diode laser at 785 nm.…”