| Owing to their intriguing optical electromagnetic properties, such as Located Surface Plasma Resonance Absorption (LSPRA), scattering, fluorescent quenching and so on, Gold nanoparticles (Au NPs) have already been widely applied in the fields of colorimetric analysis, fluorescence-based analysis, electrochemical analysis and Raman scattering-based analysis.2,6-bis(2-benzimidazyl)pyridine (Bbimp), is a special tridentate ligand light emitting material, whose researches are generally focused on the structures and properies of its metal complexes. In this paper, we apply Au NPs and Bbimp in the analysis of small molecule drugs based on their optical characteristics. The detail contents are as follows:(1) The Au NPs with 13 nm were synthesized, and a simple and rapid fluorescence analysis for the detection of captopril was proposed based on the special optical properity of Au NPs. As we all known, the extinction coefficient of Au NPs is about 3-5 orders of magnitude higher than traditional fluorescent dyes, so Au NPs posses the high fluorescent quenching efficiency. Based on this special properity, we constructed an energy donar-acceptor couple of acridine orange and Au NPs. By addition of captopril, acridine orange was departed from the surface of Au NPs because of the forming of Au-S covalent bond, and then the energy transfer between acridine orange and Au NPs was interfered, resulting in the fluorescence recovery of the system. There was a good linear relationship between the relatively fluorescence intensity (ΔF) and the captopril concentration in the range of 4.0×10-7 mol/L～2.0×10-6 mol/L, with the detection limit (3σ/k) of 7.1×10-8 mol/L. Besides, captopril tablets were determined according to the proposed method, the recovered of samples were 93 % and 102% with RSD lower than 2.15%(n=5).(2) Based on the LSPRA characteristic of Au NPs, we developed a lable-free determination of adenosine disodium triphosphate (ATP) by controlling the assembbies and dissociations of Au NPs in which Au NPs were as the colorimetric probe. In weak acid condition, the dispersed Au NPs were formed into assemblies in the presence of melamine, and the color of Au NPs was changed into blue. Upon addition of ATP, ATP molecules could compete with melamine to adsorb on the surface of the Au NPs, with the amount of ATP increasing, the assembiles of Au NPs were dissociated gradually, and the color of the solution was recovered to the oringial wine red. Based on this strategy, we could realize the visualized detection of ATP. It was found that the absorbance ratio at 660/518 nm of Au NPs was linear with the logarithm of ATP concentration in the range of 0.6×10-7 mol/L～2.0×10-7 mol/L, with the linear coefficient of 0.993. It was also found that common anions such as phosphates and halogens had no response while some other nucleotides including ADP, GTP and CTP had interference. We speculated that this was related to the adsorption ability of different nucleotides on the Au NPs.(3) We synthesized an organic fluorescent molecule named Bbimp, and developed a quantitative determination of Mercaptopurine (MP) based on the fluorescence "off-on" signal of Bbimp. Bbimp is a tridentate ligand which showed a strong fluorescence in the ultraviolet region. In our experiment, we studied the interaction bwtween Bbimp and Cu+, and proposed a fluorescence method for the dection of MP by the addition of MP into Bbimp-Cu2+ solution in which MP could compete with Bbimp to bind Cu2+, resulting the fluorescence recovery of Bbimp. The linear range was 4.0×10-6mol/L～7.0×10-5 mol/L and the detection limit (3σ/k) was 3.0×10-7 mol/L. with the proposed method, the analysis of MP in human urine was made with the recovery of 96.7%～107.3% with the relative standard deviation lower than 1.97% (n=3). |
PDF Full Text Request