Individual Plasmonic Nanoprobes for Biosensing and Bioimaging: Recent Advances and Perspectives

Abstract

With the advent of nanofabrication techniques, plasmonic nanoparticles (PNPs) have been widely applied in various research fields ranging from photocatalysis to chemical and bio‐sensing. PNPs efficiently convert chemical or physical stimuli in their local environment into optical signals. PNPs also have excellent properties, including good biocompatibility, large surfaces for the attachment of biomolecules, tunable optical properties, strong and stable scattering light, and good conductivity. Thus, single optical biosensors with plasmonic properties enable a broad range of uses of optical imaging techniques in biological sensing and imaging with high spatial and temporal resolution. This work provides a comprehensive overview on the optical properties of single PNPs, the description of five types of commonly used optical imaging techniques, including surface plasmon resonance (SPR) microscopy, surface‐enhanced Raman scattering (SERS) technique, differential interference contrast (DIC) microscopy, total internal reflection scattering (TIRS) microscopy, and dark‐field microscopy (DFM) technique, with an emphasis on their single plasmonic nanoprobes and mechanisms for applications in biological imaging and sensing, as well as the challenges and future trends of these fields.

Optical Microscopy Systems for the Detection of Unlabeled Nanoparticles

“…Due to their overall good biocompatibility, the possibility of surface functionalization with biomolecules and their tunable optical properties, AuNPs are suitable components of optical biosensors useful for many optical imaging techniques. 29 , 60 , 150 , 151 …”

“… 146 Thus, the features of Rayleigh scattering of NPs, including peak wavelength and spectral bandwidth, depends on the structural properties, composition and local environment of the NPs. 150 Microscopes with white light illumination and dark-field optics allow the discrimination of light scattering from individual NPs with different size and/or shape due to different optical resonances. Light scattering and absorption also depend on the environment, which allows the use of single NPs as a nanosensors for ultrasensitive detection of various biological and chemical analytes.…”

Plasmonic locator with sub‐diffraction‐limited resolution for continuously accurate positioning

“…[11][12][13][14][15][16][17][18][19][20][21][22] As one of the great advances in plasmonics, plasmon ruler, which is developed to investigate micro/nano interactions through nanoscale distance-dependent plasmon coupling of a homotypic pair of plasmonic nanoparticles, [3][4]23] has become a powerful optical tool for exploring conformational dynamics of a single protein, [24] localized mechanical force transduction, [25] and the interactive biophysics and biochemistry between two components, such as complementary DNA sequence, [8,26] enzyme-substrate, [27] and chemical reaction substrates. [28] Different from the scattering imaging of a single plasmonic nanoprobe, which reveals the ensemble of reaction, [29][30][31][32][33][34][35][36][37][38][39] interaction, [40][41][42][43], and connection processes [44][45] occurred on the surface of the probe, the plasmon ruler enables the recognition of molecular binding [3,24,[26][27] and chemical reaction events [28] at the single-mole...…”

A wafer-scale fabrication method for three-dimensional plasmonic hollow nanopillars

“…[3][4][5][6][7] In this case, localized surface plasmon resonance constitutes a versatile technique that exploits the sensitivity of plasmonic structures to a small change in the refractive index caused by (bio)molecules or more complex systems like polymers near the nanostructure vicinity. [8][9][10] In Raman spectroscopy, surface plasmon resonances contribute dominantly to the excitation of vibrational modes of molecules near metallic surfaces, giving rise to the phenomenon known as surface-enhanced Raman spectroscopy (SERS). 11,12 The resonance frequency and modal behavior of the nanostructured surface can be fine-tuned by controlling the surface morphology of a collection of structures and the physical and/or chemical composition of a single structure.…”