| During the past two decades,noble metal nanoparticles(MNPs)that can give rise to localized surface plasmon resonance(LSPR)scattering and absorption have attracted considerable attention due to their unique optical characteristics and have found extensive applications in the fields of material science,chemical and biological sensing,disease diagnosis and therapy,etc.Even though many technique was developed to imaging MNPs such as darkfield microscopy,differential interference contrast microscopy,orthogonal polarization microscopy,hotothermal imaging,and transient absorption imaging.To the best of our knowlage,up to now there have no satisfied teachnique image MNPs in high Rayleigh scattering background system,such as capillary,three-dimensional cellular or tissue imaging.Unlike fluorescence signal,the LSPR target signal shares the same detection wavelength and cannot be eliminated by spectral filters,leading to severe interference to single particle sensing.Recently,light-sheet microscopy or single plane illumination microscopy(SPIM)has gained much popularity due to its promising applications in 3D optical slicing of live biological samples such as embryos,cells,and tissues.In a typical SPIM setup,a thin sheet of light through a series of optics illuminates the sample at 90° to the optical axis of the objective lens to collecting the emission.When the thickness of the light sheet matches the depth of the focus of the lens,little sample outside the focal plane is illuminated theoretically,resulting in images with high resolution along the vertical direction,minimum out-of-focus background,and reduced Rayleigh scattering background.However,existing SPIM setups were all developed in the context of fluorescence microscopy,and there has been no report on light-sheet LSPR imaging.In this paper,our researching focused on the setup of light sheet microscopy for LSPR imaging,mainly including as the following:(1)Based on light sheet illumination microscopy,we using supercontinouum laser as the light source and optimized the detectors and other optics to develope a single light sheet LSPR imaging technique which shows excellent character licluding high sensitivity,high signal noise ratio,high temporal and spatial and anisotropy resolution.Using light sheet illuminating technology,we combined capillary system to acquire some information of nanoparticles in capillary with scattered light intensity,spectra,number,and so on.Given the fast growth of applications of plasmonic metal nanoparticles in various fields,we expect this highly sensitive and high throughput plasmonic imaging technique to be potentially useful in characterization and evaluation of MNPs as well as their dynamic interactions with surrounding environments.(2)In order to realize ultra-high sensitively analysis of Severe Acute Respiratory Syndrome(SARS),we successfully implemented the homemade supercontinuum light sheet laser microscope to the detection of SRAS-related DNA sequences at the single particle level.The principle was based on the aggregation of gold nanoparticles when Au-ssDNA nanoparticle probes hybridizing to the target ssDNA in solution leads the reducing the amount of particles.The target DNA concentration was measured by counting the variation of the simgle paricles number of 18 nm gold particles.Furthermore,Exonuclease I(Exo I)plays an important role in the process of replication,recombination,repair of DNA.Therefore,using our home made device,an efficient,rapid method was developed for the detection of the concentration of Exo I.The digestion reaction between Exonuclease I and DNA would induce the aggregation of 13 nm GNPs.Result shows there was a good linear relationship with the Log(Exo I)and the number of 13 nm GNPs aggregates.(3)We studied the oxidation kinetics of individual gold nanorods(GNRs)by using laboratory-built supercontinuum laser plane illumination dark-field imaging system based on capillary-slotted vial array of auto-sampling system.We found that different oxidation behavior of GNRs with different surface modified compounds and the reaction-induced the variation of charge by analyzing the variation of nanoparticles' color,scattered light intensity,spectra and electro-mobility,which implies the oxidation mechanism of GNRs.(4)Intracellular viscosity was in close correlation with life works and diseases,but there is rarely viscosity probes which can image in living cells.Therefore,we developed a GNR based novel viscosity probe by using a laboratory-built supercontinuum laser plane illumination dark-field imaging system which can also image in living cells.We studied the impact of the solution viscosity on the rotational dynamics of GNRs and found that the viscosity strongly influenced the rotating movement of GNRs.(5)Creating color difference and improving the color resolution in digital imaging is crucial for better application of color analysis.Herein,a novel color modulation analysis strategy was developed by using a homemade tunable multiband laser illumination device,in which the portions of R,G,and B components of the illumination light are discretionarily adjustable,and hence the sample color could be visually modulated continuously in the RGB color space.Unlike the traditional continuous-wave light source illumination,multiband laser illumination could enlarge the color separation between samples,thus resulting in high spectral sensitivity in color analysis.With this instrument and single Ag@AuNRs as the sulfide probe,we achieved high throughput and highly sensitive detection of sulfide at a detection limit of 0.1 nM,a more than 2 orders of magnitude improvement compared to the previous color sensing scheme.This strategy could be utilized for nanoparticle identification,evaluation,and determination in biological imaging and biochemical analysis,and it is expected to be used in face recognition and anti-counterfeiting technology. |
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