Two-photon Fluorescent Probes Based On Naphthalene Derivatives And Their Applications In Bioimaging

Detecting and real-time monitoring biological molecules in complicated living system is great importance of diagnosing disease early.However,the traditional fluorescent molecular dyes are excited by one-photon light,with a series of shortcomings,such as photobleaching phenomenon effect,low tissue penetration depth,interference from auto-fluorescence,as a result of short excitation wavelength.These drawbacks limit their biological applications.Two-photon fluorescence imaging technology,based on two-photon fluorescence probe which excited by two near-infrared laser pulses,can overcome single-photon probe shortcomings,and can provide better spatial resolution,reducing the photo-damage to the sample.Therefore,compared with the traditional one-photon fluorescence imaging technology,two-photon fluorescence imaging technology is more suitable for complex life system.In this dissertation,a series of two-photon fluorescent probes were synthesized and applied in complex life system:In Chapter 2,based on specific recognition and reduction of nitroreductase to nitro group under hypoxic conditions,an efficient turn-on fluorescence probe P-NTR for nitroreductase was developed by employing a p-nitrobenzyl group to naphthalene derivatives.P-NTR was applied to detect the activity of nitroreductase in cells effectively.Nitroreductase can specifically reduce the nitro group of the P-NTR,and release the fluorescence dye,leading fluorescence enhancement.P-NTR showed high selectivity and a high sensitivity for nitroreductase with linearly proportional at the concentration range of 0.05-0.9?g/mL.The detection limit was calculated to be 20 ng/mL.P-NTR was also applied to the detection and imaging of nitroreductase active in tissues under hypoxia with satisfactory results.In Chapter 3,based on the specific reaction of polysulfide to 2-fluoro-4-nitrobenzoate group,a new ratiometric two-photon fluorescent probe TPR-S for polysulfides detection was developed by employing 2-fluoro-4-nitrobenzoic acid to two-photon fluorescent dyes.TPR-S was applied to detect polysulfide in cells and tiusse effectively.Polysulfide reacts with the 2-fluoro-4-nitrobenzoate group of TPR-S and releases the fluorescent dye,leading the fluorescence signa intensity reducing at the 448 nm and enhancement at 541 nm.TPR-S showed high selectivity and a high sensitivity for poly sulfides with linearly proportional at the concentration range of 1-16 ?M.The detection limit was calculated to be 0.7 ?M.TPR-S was applied to the detection and imaging of polysulfide in the samples of acute organs injury caused by sepsis,with satisfactory results.In Chapter 4,based on the fact that glutathione will react with electrophilic groups in the present of glutathione S-transferase,an efficient turn-on fluorescence probe,P-GST,for glutathione S-transferase activity was developed by employing a 2,4-dinitrobenzenesulfonate group to naphthalene derivatives.P-GST was applied to detect the activity of glutathione S-transferase in cells and tissues effectively.In the present of glutathione S-transferase,glutathione can specifically react with the 2,4-dinitrobenzenesulfonate group of the P-GST,and release the fluorescence dye,leading fluorescence enhancement.P-GST showed high selectivity and sensitivity for glutathione S-transferase with linearly proportional at the concentration range of 0.04-0.5 ?g/mL.The detection limit was calculated to be 35 ng/mL.P-GST was applied to the detection and imaging of glutathione S-transferase in the samples of drug-induced liver damage with satisfactory results.In Chapter 5,based on the specific reaction of palladium ion to propynyl group,an efficient turn-on fluorescence probe,P-Pd,for palladium ion was developed by employing a propynyl group to Hydroxyphenylquinazolinone(HPQ).P-Pd showed high selectivity and sensitivity for palladium ion,with linearly proportional at the concentration range of 1.5-48 ?M.The detection limit was calculated to be 0.65 ?M.P-Pd was applied for palladium ions detection and imaging in cells and tiusse with satisfactory results.