Construction Of Lanthanide Luminescent Nanoprobes For Biological Analysis

Biomolecules play critical roles in biological activities,and they are closely related to various disease conditions.The highly selective and sensitive detection of biomolecules is beneficial for early detecting and monitoring of diseases.Owing to the merits of high sensitivity,high spatiotemporal resolution,and real-time in situ visualization,fluorescent probes have become one of the powerful tools for biosensing and bioimaging.Due to the advantages of deep tissue penetration,low background fluorescence interference,and low photodamage,lanthanide-doped nanoparticles（LnNPs）,a kind of luminescent nanoparticle that can be excitated by near-infrared photons,have arouse extensive attention in bioanalysis and biomedical research fields.However,there are some problems needed to be solved for LnNPs,including poor water-solubility and no recognition sites on their surface.Therefore,it is necessary to modify the surface of LnNPs and combine recognition groups for the construction of lanthanide luminescent nanoprobes.Based on this,a series of lanthanide luminescent nanoprobes with high biocompatibility,high selectivity,high specificity,and high stability were separately fabricated for the detection of disease-related biomolecules.The research contents are as follows:（1）Construction and application of cysteine/homocysteine-responsive ratiometric upconversion nanoprobesIn this study,an upconversion nanoprobe（U-NBD）was constructed by combing LnNPs and organic small molecule NBD-DTC through the amphiphilic polymer coating for cysteine/homocysteine（Cys/Hcy）ratiometric sensing.U-NBD nanoprobes showed good water solubility and low cytotoxicity,and avoided probe consumption caused by large amounts of glutathione.U-NBD nanoprobes can be able to sensitivly detect Cys/Hcy in buffer solution,and can be applicable for Cys/Hcy imaging in living cells.（2）Construction and application of adenosine triphosphate-responsive ratiometric upconversion nanoprobesIn this study,an upconversion nanoprobe（U-C）was constructed by combing LnNPs and carbon dots（CDs）via the coordination interaction for lysosomal adenosine triphosphate（ATP）ratiometric sensing.The exsitence of CDs not only achieved the surface modification of LnNPs,but aslo endowed U-C nanoprobe with high selectivity and biocompatibility.U-C nanoprobes can be able to detect ATP in acidic buffer solution,and can monitor lysosomal ATP in cells and mouse liver tissue slices in the model of drug-induced liver injury.（3）Construction and application of hydrogen sulfide-responsive lanthanide luminescent nanoprobesIn this study,a lanthanide luminescent nanoprobe（LnNPs@IR）was constructed by combing LnNPs and NIR organic small molecule IR-1048 through the amphiphilic polymer coating for hydrogen sulfide（H₂S）dual-channel sensing（green channel,540 nm and NIR-II channel,1525 nm）.LnNPs@IR nanoprobes were easily prepared,had good water solubility and low cytotoxicity,and showed a rapid,highly sensitive and selective luminescence off-on response to H₂S.LnNPs@IR nanoprobes can be able to sensitivly detect H₂S in buffer solution,and can be applicable for H₂S imaging in living cells.