Electrochemiluminescence Spectra And Imaging Techniques For Analytical Applications

Electrochemiluminescence(ECL)sensing technology has some advantages such as simplified device,low cost,good repeatability,high sensitivity,good stability,and low background,so it is widely used in the construction of high sensitivity molecules and identification methods.Traditional ECL detection technologies based on photomultiplier tubes have the most obvious advantages of low detection limit and high sensitivity,but they still have disadvantages such as insufficient luminescence stability and poor luminescence selectivity.At present,developed the double-signal ratiometric technique sensors could effectively normalize the variation in environmental changes,and thus offer more precise and stable sensing properties in analytical application.On the other hand,the ECL imaging technologies based on charge-coupled device(CCD)can realize the visual detection of micro region and play an increasingly important role in the field of life analysis.Because the ECL imaging technology has high spatial resolution and high throughput,it significantly promotes the development of microarray techniques,single particle electrochemical study,cell imaging and other fields.Based on the above research background,we develop two new ECL detection methods which could be applied in the field of life analysis.The main contents were described as below:1.Hydrogen sulfide Sensing based on ECL Spectral ShiftHydrogen sulfide(H2S),as a toxic gas,has emerged as the third endogenously produced gaseous signaling molecule besides nitric oxide(NO)and carbon monoxide(CO).The abnormal production of H2S has been associated with diseases such as chronic alzheimer's and Down's syndrome.Therefore,it is great significance of the accurate determination of H2S.The traditional ECL detection methods usually depended on the change of luminescence intensity to realize quantitative detection.However,this detection mode is easily interfered by other substances in the complex reagent samples,resulting in deviation of detection results.Therefore,we designed a detection method based on ECL spectral shift.This method use Ru(bpy)32+as the ECL luminophore,CouMC(a hybrid fluorophore of coumarin and merocyanine)as the probe to identify H2S.By measuring a change in the maximum luminescence wavelength of the ECL luminophore,we achieve the quantitative detection of H2S.Experimental results suggest that the spectral shift of ECL effectively avoids the interference of the total luminescence intensity fluctuations.Thus,the interference caused by ECL intensity fluctuation is avoided,and the stability and selectivity is improved.The spectral shift-based ECL assay strategy as a new detection method offers a wide application platform by extending types of ECL luminophores and absorptive chemodosimeters.2.Imaging Local Cu2+Concentration based on Single-nanoparticle Electrochemiluminescence MicroscopyWe proposed a Cu2+ sensing method based on single nanoparticles by using ECL microscopy.Graphite-like Carbon Nitride(g-C3N4)was used as the single ECL response probe,and Cu2+was used to quench the single g-C3N4 ECL luminescence to realize the imaging analysis of local concentration of Cu2+.The effects of the coreactant concentration and pH of electrolyte have been studied in detail.When there is no Cu2+ in the system,g-C3N4 has obvious ECL emission.However,with the continuous addition of Cu2+,the ECL luminescence of a single g-C3N4 can be effectively quenched with short response time and good selectivity.Importantly,we successfully used the g-C3N4 sensor to detect Cu2+secreted by cancer cells,which is of great significance for the study of single cell heterogeneity.The single-nanoparticle ECL imaging technique achieves a high throughput,quickly response,high spatial-temporal resolution detection platform,and thus has wide application value in single particle and single-cell level research.