A microscopic fluorescence spectrometric analysis ( MFSA) system was set in the laboratory. A novel method for in situ determination of Anthracene ( Ant) adsorbed onto root surface micro-zone of two kinks of mangrove plant, named Kandelia obovata ( K. obovata) and Avicennia marina ( A. marina) by MFSA was established. Fluorescence spectra of Ant adsorbed on root surface micro-zone were obtained by synchronous scanning mode. The signal to noise (S/N) of Ant (5. 3 pg/μm2) adsorbed on K. obovata and A. marina root surface micro-zone increased up to 5. 5 and 6. 8 while wavelength offset (△λ) both were at 60 nm, respectively. The linear dynamic ranges of established method were 5. 3-63. 2 pg/μm2 for K. obovata and 10. 5-52. 6 pg/μm2 for A. marina, with the detection limits of 1. 1 pg/μm2 and 5. 5 pg/μm2 , respectively. The relative standard deviations were both less than 12 . 5% ( n=9 ) , and the recoveries were 98 . 1% -117. 0% and 81. 2%-110. 9%, respectively. The result showed that the MFSA system had ability to obtain quantitative information of fluorescence spectra and fluorescence image of Ant adsorbed onto plant roots surface micro-zone.

Targeted programmed death-ligand 1 (PD-L1) and CXC chemokine receptor type 4 (CXCR4), gene sequences encoding anti-PD-L1 nanobody and anti-CXCR4 nanobody were cloned into the pET-22b (+) vector to construct recombinant expression plasmid of anti-PD-L1&CXCR4 bispecific nanobody, which was connected with 6 × His tag and transformed into E.coli BL21 (DE3). The expressed proteins were then found to exist as a soluble form in the supernatant of bacterial lysate after induction of IPTG.Three purification methods were used to obtain the target protein in order to improve the yield and purity of the bispecific nanobody.The bacterial supernatant was separated and purified by His Trap FF affinity chromatographic column.The target protein output could exceed 1 mg/L, and the product purity could reach up to 97%.Besides, the anti-PD-L1&CXCR4 bispecific nanobody shows a specific binding ability to two antigens on the cell surface, enhancing the cytotoxicity of IL-2 activated human peripheral blood mononuclear cells (PBMC) to tumor cell line AsPC-1, which lays the foundation for further evaluation of its drug efficacy in vivo.