Runping Jia

A highly sensitive assay for protein with dibromochloro-arsenazo-Al3+ using resonance light scattering technique and its application

A simple, sensitive and selective method has been developed for the determination of protein using resonance light scattering (RLS) technique. The method is based on the interaction of protein and arsenazo-DBC-Al(3+) in the pH range of 5.0-7.0, which causes a substantial enhancement of the resonance scattering signal of arsenazo-DBC-Al(3+) in the wavelength range of 300-550 nm with the maximum RLS platform at 405-420 nm. With this method, 2.50-50.00 mug ml(-1) of bovine serum albumin (BSA) and 2.50-60.00 mug ml(-1) of human serum albumin (HSA) can be determined, and the detection limits, calculated three times the standard deviation (S.D.) of six blank measurements, for BSA and HSA were 123.4 and 89.6 ng ml(-1), respectively. Moreover, the method is free from interference from many amino acids and metal ions. The method, with high sensitivity, selectivity and reproducibility, was satisfactorily applied to the determination of total protein in human serum samples. Mechanism studies indicated that arsenazo-DBC-Al(3+) could bind to BSA depending mainly on electrostatic forces, which results in enhanced RLS in the arsenazo-DBC-Al(3+)-protein system.

Quantitative determination of proteins by the Rayleigh light-scattering technique after optimization of the derivation reaction with Arsenazo-DBS

This paper researched the determination of proteins with 2-(2-arsonophehenylazo)-7-[(2,6-dibromo-4-sulfophenylazo)1,8-dihydroxynaphthalene-3,6-disulfonic acid (Arsenazo-DBS) by Rayleigh light-scattering (RLS). The reaction parameters, such as acidity, volume of buffer solution and concentration of Arsenazo-DBS, were examined by orthogonal array design (OAD). Under optimal conditions, the weak RLS of Arsenazo-DBS and BSA can be enhanced greatly and two enhanced RLS signals were produced at 340-350 and 400-420 run. Based on this reaction, a new quantitative determination method for proteins has been developed. This method is proved to be very sensitive (the determination limits are 0.077 mug ml(-1) for bovine serum albumen (BSA) and 0.074 mug ml(-1) for human serum albumen (HSA)), rapid (<2 min), simple (one step) and tolerance of most interfering substances. The effects of different surfactants were also examined. The amount of proteins in human serum samples was determined and the maximum relative error was no more than 2% and the recovery was between 95 and 105%

Study of the reaction of proteins with Beryllon II–AlIII by the Rayleigh light scattering technique and its application

The determination of proteins with tetrasodium 2-(3,6-disulfo-8-hydroxynaphthylazo)-1,8-dihydroxynaphthalene-3,6-disulfonate (Beryllon II) by Rayleigh light scattering (RLS) was studied. The weak RLS of the Beryllon II-bovine serum albumin (BSA) complex can be greatly enhanced by the addition of Al3+ in the pH range 5.6-7.2; there was a maximum RLS platform at 400-420 nm. Based on the reaction between Beryllon II, Al3+ and proteins, a new method for the determination of proteins was developed. This method is very sensitive [0.20-41.42 micrograms ml-1 for BSA and 0.18-48.15 micrograms ml-1 for human serum albumen (HSA)], rapid (< 2 min), simple (one step) and tolerant towards most interfering substances. The effects of different surfactants were also examined. Four samples of protein in human serum were determined; the maximum relative error was no more than 5% and the recovery was 96-105%.

Photoluminescence spectra of human serum albumen and morin embedded in porous alumina membranes with ordered pore arrays

For the first time, an organic dye, morin, and another bio-macromolecule, human serum albumen (HSA), were embedded in porous alumina (P-Al) fabricated by anodization in oxalic acid. The photoluminescent (PL) spectra of morin and morin–HSA immersed in the P-Al pores were measured and compared with those of liquid solutions. It was found that their PL positions are similar to those of dye-Al3+ in ethanol solution, and the PL of the embedded morin was greatly enhanced by the introduction of HSA. We have ascribed the appearance of PL bands to the formation of morin–Al complexes in the nanopores, with its inner wall being involved. A likely luminescence model was proposed to explain the observed PL enhancement due to the coexistence of morin and HSA in the nanopores, which has been proved by UV and Fourier transform infrared measurements. Moreover, the PL intensity increased with increasing pore diameter, which may be used to develop a luminescent array to predict the pore size of a P-Al layer.

RAYLEIGH LIGHT SCATTERING ENHANCING REACTION OF DIBROMOCHLOROARSENAZO AND PROTEINS SYSTEM AND ITS ANALYTICAL APPLICATION

Based on the enhancement effects of Rayleigh light scattering (RLS) on Arsenazo-DBC, a novel quantitative method for the determination of proteins in aqueous solutions has been proposed. The reaction of Dibromochloroarsenazo (Arsenazo-DBC) and five proteins (BSA, HSA, egg albumin, human γ-IgG, Lysozyme) has been studied. Under optimal conditions the dynamic ranges for proteins were 2.5–60.0 μg·ml−1, and the detection limits for HSA and BSA were at 98.50 ng·ml−1 and 88.10 ng·ml−1, respectively. Comparing with other methods, the method is simple, practical and relatively free from interference from coexisting substances. The method was employed for the determination of total protein in human serum with satisfactory results.

Enhanced photoluminescence of morin–bovine serum albumin on porous anodized aluminum oxide

In this paper, the photoluminescence (PL) of porous anodized aluminum oxide (AAO) impregnated with essentially nonfluorescent morin and morin-bovine serum albumin (BSA) was investigated for the first time, respectively. The evident PL bands similar to that of morin-Al3+ complex in solution were observed and the intensity of the latter with morin-BSA was much greater than that of the former with only morin. Moreover, the enhancement increased with the larger pore diameter of the AAO membranes. The appearance of PL bands might be ascribed to the formation of morin-Al complexes in the AAO pores with its inner wall involved. A likely orderly luminescent model was proposed to be responsible for the observed enhancing phenomena of PL due to the coexistence of morin and BSA in the AAO pores.