Nano-Confined Effect and Heterojunction Promoted Exciton Separation for Light-Boosted Osmotic Energy Conversion.

The osmotic energy conversion properties of biomimetic light-stimulated nanochannels have aroused great interest. However, the power output performance is limited by the low light-induced current and energy conversion efficiency. Here, nanochannel arrays with simultaneous modification of ZnO and di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,20-bipyridyl-4,40-dicarboxylato) ruthenium (II) (N719) onto anodic aluminum oxide (AAO) to combine the nano-confined effect and heterojunction is designed, which demonstrate rectified ion transport behavior due to the asymmetric composition, structure and charge. High cation selectivity and ion flux contribute to the high power density of ≈7.33 W m-2 by mixing artificial seawater and river water. Under light irradiation, heterojunction promoted the production and separation of exciton, enhanced cation selectivity, and improved the utilization efficiency of osmotic energy, providing a remarkable power density of ≈18.49 W m-2 with an increase of 252% and total energy conversion efficiency of 30.43%. The work opens new insights into the biomimetic nanochannels for high-performance energy conversion.

A rapid and sensitive chemiluminescent immunoassay of total thyroxin with DMAE x NHS-Labeled.

A novel chemiluminescence immunoassay (CLIA) of total thyroxin (TT4) with the acridinium ester of DMAE x NHS [2',6'-dimethyl-4'-(n-succinimidyloxycarbonyl) phenyl-10-methyl-acridinium-9-carboxylate methosulfate] labeled has been developed. In our method, microwells were coated with anti-T4 monoclonal antibody (McAb) and DMAE x NHS synthesized by our laboratory was conjugated with streptavidin (SA). T4-BSA was conjugated with biotin-N-hydroxysuccinimide (B x NHS), T4-BSA- B x NHS and the T4 in the standard or sample competitively react with anti-T4 McAb. Streptavidin-biotin separation and enhanced techniques were applied in this assay. The presented approach shows many excellent characteristics, particularly, rapid assay process and high detection sensitivity.

Sensitive time-resolved fluoroimmunoassay for simultaneous detection of serum thyroid-stimulating hormone and total thyroxin with Eu and Sm as labels.

Based on a novel cocoating strategy and dissociation enhancement lanthanide fluorescence immunoassay technique, a sensitive time-resolved fluoroimmunoassay (TRFIA) has been developed for simultaneous quantification of human serum thyroid-stimulating hormone (TSH) and thyroxin (T4) in a one-and-the-same assay procedure. The new cocoating strategy for preparing highly active surface anti-TSH and anti-T4 monoclonal antibodies (McAbs) was performed by a three-step protocol. Namely, anti-TSH McAb at high concentration (10 micro g/ml) and extensively biotinylated bovine serum albumin (BSA) at low concentration (0.5 micro g/ml) were coated on microwells by passive adsorption, then streptavidin was captured by the surface BSA-biotin, and finally biotinylated anti-T4 McAb was immobilized by the remnant binding sites of the bound streptavidin. In the present TSH/T4 TRFIA, both sandwich- and competitive-type configurations were involved, and Eu(3+) and Sm(3+) were used as labels for TSH and T4 detection, respectively. The method showed rapid kinetics; the equilibrium was reached within 30min at 37 degrees C due to the use of high concentrations of reaction reagents, rapid agitation, and small reaction volume. The lower limits of detection of the method were 0.028 mIU/L for TSH and 4.1 nmol/L for T4 with 20 micro L of sample volume. The assay ranges for TSH and T4 were 0.21-80.00 mIU/L and 20-300 nmol/L, respectively. The correlation between the TSH/T4 values obtained by the present TSH/T4 TRFIA and those obtained by commercial chemiluminescence immunoassay was satisfactory.

Synthesis of a highly fluorescent beta-diketone-europium chelate and its utility in time-resolved fluoroimmunoassay of serum total thyroxine.

A new highly fluorescent beta-diketone-europium chelate was synthesized and employed as a tracer to develop a time-resolved fluoroimmunoassay (TRFIA) for detection of serum total thyroxine (T4). The tetradentate beta-diketone chelator, 1,10-bis(thiophene-2'-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone (BTOT), was structurally composed of two units of thenoyltrifluoroacetone (TTA) derivatives but expressed fluorescence that was greatly enhanced, as compared to the original TTA molecules, in the presence of excess amount of Eu3+. The luminescence properties of the europium chelate of BTOT werestudied in aqueous solution. Chlorosulfonylation of BTOT afforded 1, 10-bis(5'-chlorosulfo-thiophene-2'-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone (BCTOT), which could be coupled to proteins (i.e., streptavidin or the BSA-T4 conjugate) and used as a tracer for TRFIA. Although the BCTOT-Eu complex could be detected at a very low level (approximately 1.07 x 10(-12) mol/L) in buffered aqueous solution (50 mmoVLTris-HCl; pH, 8.0), the application of the chelate label in direct serum T4 TRFIA experienced a problem of matrix interference, which was probably caused by some unknown chelating components in the samples as a result of the fact that the fluorescence of the BCTOT-Eu chelate was prone to quenching or enhancement by some chelating reagents. To remove this problem, an indirect serum T4 TRFIA was proposed with the use of BCTOT-Eu-labeled streptavidin (SA) as signal generation reagent. The concentrations of T4 in 27 human serums were determined by indirect T4 TRFIA, and the assay results correlated well with those obtained by commercial Coming-CLIA (r = 0.955) and Wallac-DELFIA (r 0.965).

Time-resolved immunofluorometry of serum hTSH with enhanced sensitivity.

Sensitive TSH immunoassays offer a clear advance in discriminating the TSH concentrations in serum between hyperthyroid and euthyroid individuals; they have been proposed as the best single screening test for thyroid disorders. We have developed a highly sensitive serum TSH TRFIA based on DELFIA technology. Three monoclonal antibodies (McAbs) directed against different epitopes of the TSH molecule were involved in this assay, of which, one McAb was used to coat clear microwells, and the other two were biotinylated' for signal generation after being bound by the europium labeled streptavidin. The europium label captured on the well surface was quantified by a routine dissociation-enhancement procedure. The fluorescence intensity was directly proportional to the serum hTSH concentration. The assay required two steps and could be completed within 5 h. The analytical sensitivity reached 0.002 mIU/L with a sample volume of 100 microL, the function sensitivity was 0.017 mIU/L. Measurements by the present method correlated well with that obtained by the ACS-180 chemi-luminescence immunoassay (CLIA). The discrimination of hyperthyroid patients from clinically euthyroid patients by the present method was much better than that by the routine IRMA.