Recent Progress of SERS Nanoprobe for pH Detecting and Its Application in Biological Imaging

Abstract

As pH value almost affects the function of cells and organisms in all aspects, in biology, biochemical and many other research fields, it is necessary to apply simple, intuitive, sensitive, stable detection of pH and base characteristics inside and outside the cell. Therefore, many research groups have explored the design and application of pH probes based on surface enhanced Raman scattering (SERS). In this review article, we discussed the basic theoretical background of explaining the working mechanism of pH SERS sensors, and also briefly described the significance of cell pH measurement, and simply classified and summarized the factors that affected the performance of pH SERS probes. Some applications of pH probes based on surface enhanced Raman scattering in intracellular and extracellular pH imaging and the combination of other analytical detection techniques are described. Finally, the development prospect of this field is presented.

Activatable Probes for Ratiometric Imaging of Endogenous Biomarkers In Vivo

“…SERS imaging with high photostability and sensitivity for the detection of small molecules at the single-molecule level is a promising molecular detection and imaging platform for the sensitive detection of biomarkers overexpressed in the TME. − For example, Song and co-workers designed a Cu 2+ -responsive probe (AuNNP-NAT@MBN/PNIPAM) consisting of two types of Raman molecules for ratiometric SERS detection of urinary Cu 2+ of WD patients (Figure a) . The Cu 2+ concentration-dependent Raman signal ratio ( I 2223 / I 1378 ) enhancement was achieved based on the probe’s design (Figure b).…”

Design and performance of pH-responsive cyano-Raman label SERS probes based on single urchin Au nanoparticles

“…For example, by measuring the pH of water, the extent of ecosystem damage caused by acidification can be determined. 11,12 At present, the main methods for detecting the pH value are colorimetry, 13,14 ultraviolet–visible (UV-vis) region spectroscopy, 15,16 potential measurements, 17 fluorescence spectroscopy 18 and SERS probes. 19–21…”

Surface-Roughened SERS-Active Single Silver Nanowire for Simultaneous Detection of Intracellular and Extracellular pHs

“…Surface-enhanced Raman scattering (SERS) has shown great promise in the detection of cellular microenvironments due to its unique advantages of high sensitivity, strong specificity, and optical stability. , Based on the “fingerprint” scattering signal, SERS can identify the tiny structural conformation change of pH-sensitive molecules and even monitor the dynamic changes, enabling highly sensitive detection of pH in the cellular environment. , At present, the most representative signal molecules mainly used to construct pH SERS probes are 4-mercaptobenzoic acid (4-MBA), 4-mercaptopyridine (4-Mpy), and 4-aminobenzene mercaptan (4-ATP) . Among them, 4-MBA is widely used as a pH Raman reporter for cellular pH detection due to its advantages of simple structure, wide pH response range, high photochemical stability, low cytotoxicity, mercaptan-mediated metal surface affinity, and the ability to form a self-assembly monolayer on the metal surface made 4-MBA suitable for detecting pH distribution on the metal …”