Studies On The Capillary Flow Directed Assemblies On The Surfaces Of Solid Supports And Its Analytical Applications In Environmental Biochemistry

Self-assembly technique is one of the most interesting research fields in supermolecular chemistry and material sciences. Ring-like self-organization is attracting for its potential application in material sciences and bionic value. Mechanisms including evaporation induced capillary flow, 2-D bubbles and dried-hole hypotheses are discussed, and further experiments were tested concerning the analytical applications of SOR in biochemical and environmental analysis.At pH 6.62 and with the aid of poly (vinyl alcohol)-124 (PVA-124), a droplet of nuclear fast red (NFR) solution can form a fluorescent SOR on hydrophobic glass slide, and the presence of protein can enhance its fluorescence intensity. When the volume of the droplet is 0.2ul, linear response is observed in the range 0-100pg, and the limit of determination is 2.44pg for BSA and 0.9Ipg for HSA. The results of determination for three serum samples were identical with those obtained according to the Bradford method using Coomassie Brilliant Blue (CBB G-250).When the pH is 7.33, quercetin can form an SOR on a dimethyl dichlorosilane (DMCS) modified glass slides with the aid of poly (vinyl alcohol)-!24. Its maximum fluorescence intensity can be quantitatively quenched by iron (III) over the range 7.56-132.64ng/ml and the limit of determination is 2.52ng/ml. Four water samples and two human serum samples were determined satisfactorily.When a 1.0ul droplet of the fluorescent complex of aluminum (III)-eriochrome red B (ERB) was spotted to the surface of DMCS pretreated glass slide, an SOR with the outer radius of 0.70mm can be obtained. Linear response was observed between maximum fluorescence intensity of the SOR with the content of aluminum the range of 0.02-0.20pmol, and the limit of determination is 1.42fmol with three folds of signal to noise. This method was applied successfully to the determination of trace amount of aluminum (III) in a series of river samples and the results were identical with those obtained according to the standard method using Eriochrome cyanine R (ECR).An SOR method was established for the simultaneous determination of trace amounts of copper and lead. Under alkalescent conditions controlled by hexahydro -pyridine, the SOR of a,p,y,6-Tetrakis (4-sulfonylphenyl) Porphine (TPPS4) which is formed on the glass slide modified by dimethyl dichlorosilane has very strong fluorescence, but its fluorescence intensity can be quenched quantitatively by copper and lead. When the volume of the droplet is 1.0ul and content of TPPS4 is 1.08xl0-12mol/ring, linear response is observed in the range 0-l.25x10-12mol and the limit of determination is l.72fmol for copper; linear response is observed in the range 0-3.80x10-12mol and the limit of determination is 6.63 fmol for lead. Trace amounts of copper and lead in synthetic samples have been determined simultaneously and satisfactorily.Owing to the oxidation of chromium (VI). the fluorescence of an SOR of Pyronine Y (PY) is quenched by chromium (VI). This reaction can be applied to determine trace amount chromium (VI) in water samples. When the volume of the droplet is 1 .0ul and content of PY is 5.0x10-6M, linear response is observed in the range 0-30ug/l and the limit of determination is 0.50ug/l.Under low pH conditions, the addition of fluoride to the zirconium-calcein blue (CB) complex increases the fluorescence intensity that based on the formation of a strongly fluorescent 1:1:1 ternary complex. Using SOR method, fluorine can be determined down to 1.58x 10-8M and the linear range is 0-1 .0x 10-6M.