Development of a Tri-Functional Nanoprobe for Background-Free SERS Detection of Sialic Acid on the Cell Surface

Septila Renata,Nitish Verma,Rong-Long Pan,Zhijay Tu,Mario Hofmann,Chun-Hung Lin

doi:10.3390/chemosensors9050092

Septila Renata, Nitish Verma + Show 4 more

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https://doi.org/10.3390/chemosensors9050092

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Abstract

Sialic acid (SA) on the surface of cells is indispensable in numerous physiological and pathological processes, and sensitive and reproducible detection of SA is crucial for diagnosis and therapy in many diseases. Here, we developed a tri-functional nanoprobe as a sensitive and straightforward surface-enhanced Raman spectroscopy (SERS) nanoprobe for sialoglycan detection on cell surfaces. The reporter was designed to provide three key functionalities that make it ideal for SA detection. First, we employed two recognition groups, phenylboronic acid and an ammonium group, that enhance SA recognition and capture efficiency. Second, we used cyano as the Raman reporter because it emits in the cellular Raman silent region. Finally, thiol acted as an anchoring agent to conjugate the reporter to silver nanocubes to provide SERS enhancement. Our molecular nanoprobe design demonstrated the ability to detect SA on the cell surface with high sensitivity and spatial resolution, opening up new routes to cellular diagnostics.

Highlights

IntroductionSialic acid (SA) on the surface of cells is indispensable in numerous physiological and pathological processes, and sensitive and reproducible detection of SA is crucial for diagnosis and therapy in many diseases
NaHS), poly(vinyl pyrrolidone) (PVP, Mw ~55,000), hydrochloric acid (HCl, 32%), 3-formylphenylboronic acid, and 4 M HCl in 1,4-dioxane were obtained from SigmaAldrich (MilliporeSigma, MA, USA)
We report the z-average diameter, and zeta-potential values were estimated from the measured electrophoretic mobility data using the Smoluchowski equation (Malvern Instruments Ltd., Malvern, UK). 1 H NMR spectra were recorded on a Bruker

Summary

Introduction

Sialic acid (SA) on the surface of cells is indispensable in numerous physiological and pathological processes, and sensitive and reproducible detection of SA is crucial for diagnosis and therapy in many diseases. We developed a tri-functional nanoprobe as a sensitive and straightforward surface-enhanced Raman spectroscopy (SERS) nanoprobe for sialoglycan detection on cell surfaces. The reporter was designed to provide three key functionalities that make it ideal for SA detection. Our molecular nanoprobe design demonstrated the ability to detect SA on the cell surface with high sensitivity and spatial resolution, opening up new routes to cellular diagnostics. Surface-enhanced Raman spectroscopy (SERS) is a powerful detection tool with great potential for diagnostics because of advantages that include simple sample preparation, published maps and institutional affiliations

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