Resonance Rayleigh Light Scattering Research Articles

Investigation of the binding of AuNPs-6-mercaptopurine and the sensitive detection of 6-mercaptopurine using resonance Rayleigh light scattering.

A highly sensitive method for the detection of 6-mercaptopurine (MP) by resonance Rayleigh light scattering (RLS) method was developed. Gold nanoparticles (AuNPs) were synthesized by a modified seed method and characterized using transmission electron microscopy (TEM). AuNPs were bound to MP via covalent bonding to form the MP-AuNPs complex, which increased the RLS intensity of MP at 347nm (increased by 65.7%). Under optimum conditions, the magnitude of the enhanced RLS intensity for MP-AuNPs was proportional to MP concentration in the range 0.0681-1.702μgmL-1 . The linear regression equation was represented as follows: ΔIRLS = 9.31 + 82.42c (r=0.9948). The limit of detection (LOD, 3σ) was 3.32ngmL-1 . The system was applied successfully to detect MP in pharmaceuticals. MP recoveries were 99.9-101.7% with a relative standard deviation (RSD) (n=5) of 0.59-0.77% for three synthetic samples, and 97.5-110.0% with an RSD of 0.98-2.10% (n=5) for tablet samples.

Using gold nanoparticles as probe for detection of salmeterol xinafoate by resonance Rayleigh light scattering

The paper explores the method of determination of salmeterol xinafoate at nanogram level with gold nanoparticles (AuNPs) probe, to measure the intensity of resonance Rayleigh light scattering (RLS) by a common spectrofluorometer. The RLS intensity of salmeterol xinafoate was greatly enhanced by AuNPs, with the maximum scattering peak at 357nm. The salmeterol xinafoate was determined basing on the binding of salmeterol xinafoate to AuNPs by electrostatic adsorption. Under the optimum conditions, the enhanced RLS intensity was directly proportional to the concentration of salmeterol xinafoate in the range of 0.054–6.038μgmL−1 with a good linear relationship (r=0.9928). The limit of detection (LOD) was 9.48ngmL−1. The interference tests were performed carefully. With the proposed method, the synthetic samples were analyzed satisfactorily, the recovery and RSD were 102.5–103.0% and 0.67–1.0% respectively.

The resonance Rayleigh light scattering spectral investigation on the interaction of DNA with camellia sinensis in the presence of CPC and its analytical application

A novel method with high sensitivity was designed for the determination of trace nucleic acids by using cationic surfactant cetylpyridinium chloride (CPC) and camellia sinensis (CS) as resonance Rayleigh light scattering (RLS) probes. It was found DNA could combine with CS and CPC in Tris–HCl buffer (pH=7.4). Under optimum conditions, the RLS intensity of DNA can be enhanced by CPC–CS obviously at 294nm, and the enhanced RLS intensity was directly proportional to DNA concentration in the range from 0.024 to 3.48μgmL−1 with a good linear relationship (r=0.9940). The limit of detection (LOD) was 1.49ngmL−1 (S/N=3). In addition, the effects of some interferences including K+, Na+, Mg2+, Zn2+, Cu2+, Ca2+ and glucose on the determination were studied. The developed RLS assay was successfully applied to three synthetic samples to measure DNA, the recovery was 94.7–106.3% and RSD was 0.58–3.33%.

The analytical application and spectral investigation of DNA–CPB–emodin and sensitive determination of DNA by resonance Rayleigh light scattering technique

A new sensitive DNA probe containing cetylpyridinium bromide (CPB) and emodin (an effective component of Chinese herbal medicine) was developed using the resonance Rayleigh light scattering (RLS) technique. A novel assay was first developed to detect DNA at nanogram level based on the ternary system of DNA–CPB–emodin. The RLS signal of DNA was enhanced remarkably in the presence of emodin–CPB, and the enhanced RLS intensity at 340.0nm was in direct proportion to DNA concentration in the range of 0.01–2.72μgmL−1 with a good linear relationship. The detection limit was 1.5ngmL−1. Three synthetic DNA samples were measured obtaining satisfactory results, the recovery was 97.6–107.3%.

An investigation on the interaction of DNA with hesperetin/apigenin in the presence of CTAB by resonance Rayleigh light scattering technique and its analytical application

Two new systems for measuring DNA at nanogram levels by a resonance Rayleigh light scattering (RLS) technique with a common spectrofluorometer were proposed. In the presence of cetyltrimethylammonium bromide (CTAB), the interaction of DNA with hesperetin and apigenin (two effective components of Chinese herbal medicine) could enhance RLS signals with the maximum peak at 363 and 433nm respectively. The enhanced intensity of RLS was directly proportional to the concentration of DNA in the range of 0.022–4.4μgmL−1 for DNA–CTAB–hesperetin system and 0.013–4.4μgmL−1 for DNA–CTAB–apigenin system. The detection limit was 2.34ngmL−1 and 2.97ngmL−1 respectively. Synthetic samples were measured satisfactorily. The recovery of DNA–CTAB–hesperetin system was 97.3–101.9% and that of DNA–CTAB–apigenin system was 101.2–109.5%.

Determination of Protein in Milk Powder Using 2-Sulfophenylazo-Rhodanine as a Probe by the Enhanced Resonance Rayleigh Light-Scattering Technique

In this paper, the interaction between 2-sulfophenylazo-rhodanine and protein was investigated by Rayleigh light-scattering technique. Based on this, a novel method for the determination of protein was developed. The effects of different conditions, such as acidity and media, were investigated thoroughly, and the optimum conditions were confirmed. Bis(2-ethylhexyl)sulfosuccinate (AOT) microemulsion, which is introduced into the protein determination, markedly increased the sensitivity of the system by changing the microenvironment. In pH 2.80 Britton-Robinson buffer solution in the presence of AOT microemulsion, the detection limits of bovine serum albumin, human serum albumin, ovalbumin, and gamma-globulin are 5.4, 4.5, 9.8, and 10.1 ng/mL, respectively. The method developed in this paper has been applied to the determination of protein in milk powder with satisfactory results.

Visual gene diagnosis of HBV and HCV based on nanoparticle probe amplification and silver staining enhancement.

A visual gene-detecting technique using nanoparticle-supported gene probes is described. With the aid of gold nanoparticle-supported 3'-end-mercapto-derivatized oligonucleotide serving as detection probe, and 5'-end -amino-derivatized oligonucleotide immobilized on glass surface acting as capturing probe, target DNA was detected visually by sandwich hybridization based on highly sensitive "nano-amplification" and silver staining. Different genotypes of Hepatitis B and C viruses in the serum samples from infected patients were detected using home-made HBV, HCV, and HBV/HCV gene chips by the gold/silver nanoparticle staining amplification method. The present visual gene-detecting technique may avoid limitations with the reported methods, for its high sensitivity, good specificity, simplicity, speed, and cheapness. This technique has potential applications in many fields, especially in multi-gene detection gene chips coupled with the detection will find applications in clinic. Additionally, resonance Rayleigh light scattering (RLS) spectroscopy is used, for the first time, to judge and monitor the immobilization of gene probes on gold nanoparticle surfaces.

RESONANCE RAYLEIGH LIGHT-SCATTERING OF THIAMINE HYDROCHLORIDE–NUCLEIC ACIDS–CETYL TRIMETHYL AMMONIUM BROMIDE SYSTEMS AND THEIR ANALYTICAL APPLICATION

ABSTRACT Resonance Rayleigh light-scattering (RRLS) of Thiamine Hydrochloride (TH)–nucleic acids–cetyl trimethyl ammonium bromide system and its analytical application was studied by using a common spectrofluorimeter, by which nucleic acids at nanogram level can be determined. TH–CTMAB reacts rapidly with nucleic acids at room temperature and the intensity of the weak common Rayleigh light scattering (RLS) of TH–CTMAB is enhanced remarkably by nucleic acids. The effective factors were studied and the optimum conditions were obtained. In TH–nucleic acids–CTMAB system, the formation of an ion association complex of TH–nucleic acids–CTMAB is considered as the reason of the enhancement of RRLS. It was also proved that the RRLS and RLS appeared in the same light scattering process. Linear relationships were found between the enhanced RRLS intensity at 406 nm and nucleic acids concentration in the range 8.0 × 10−9–1.0 × 10−5 g/mL for fish sperm DNA (fsDNA), 2.0 × 10−8–1.0 × 10−5 g/mL for calf thymus DNA (ctDNA)...

Interaction of cetylpyridine bromide with nucleic acids and determination of nucleic acids at nanogram levels based on the enhancement of resonance Rayleigh light scattering

Resonance Rayleigh light scattering (RRLS) spectra of cetylpyridine bromide (CPB)–nucleic acid system and their analytical application have been first studied. The effective factors and optimum conditions of the reaction have been investigated. After CPB and nucleic acid are mixed together, a new absorption peak located at 300 nm appeared, which is due to the formation of new ion associate of CPB–nucleic acid. The new associate can result in two apparent RRLS peaks at 310–400 and 460–480 nm. The RRLS peak of the corrected spectra located at 290–350 nm, which indicate that the RRLS is originated from the absorption of CPB–nucleic acid associate. The peak at 460–480 nm disappears in the corrected RRLS spectra, which indicated that this peak is originated from the strong line emission of the Xe lamp. Under the optimum conditions, the enhanced intensity of RRLS is proportional to the concentration of nucleic acid in the range of 5.0×10 −9–5.0×10 −5 g ml −1 for calf thymus DNA (ctDNA), 1.0×10 −8–4.0×10 −5 g ml −1 for fish sperm DNA (fsDNA) and 1.0×10 −8–5.0×10 −5 g ml −1 for yeast RNA (yRNA). The detection limits ( S/ N=3) are 4.3, 8.7 and 7.4 ng ml −1, respectively. Synthetic samples were determined satisfactorily.

THE APPLICATION OF THE RESONANCE ENHANCED RAYLEIGH LIGHT-SCATTERING TECHNIQUE FOR THE DETERMINATION OF GOLD(III) WITH A NEW TRIAZENE REAGENT

The resonance Rayleigh light-scattering (RRLS) signal of a new triazene reagent, 1-(p-chlorophenyl)-3-(2-thiazolyl)triazene (p-ClPTT), is first synthesized and characterized in this paper, in the 450–550 nm wavelength range is enhanced remarkably by Au3 +. A new method for the determination of Au3 + by the RRLS technique in the presence of Tween-20 has been developed. The calibration graph shows good linearity over a concentration range of 5.0–800 μg/l with a detection limit of 3.0 μg/l. Except for IO4 −, SCN− and Pd2+, no other foreign ions interfere in the determination at concentrations less than 10-fold of Au3 +. The method is thus simple, sensitive and of good selectivity, and has been successfully used for the determination of trace gold in the ore samples.

A sensitive and rapid method for the determination of protein by the resonance Rayleigh light-scattering technique with Pyrogallol Red.

The resonance Rayleigh light-scattering (RRLS) technique was used to develop a simple, sensitive and selective method for the determination of proteins. The method is based on the interaction between proteins and Pyrogallol Red (PR) in the pH range 3.6-4.2, which causes a substantial enhancement of the resonance scattering signal of PR in the wavelength range 300-450 nm with the maximum scattering peak located at 347 nm. With this method, 0.25-13 microg ml(-1) of bovine serum albumin (BSA), 0.25-10 microg ml(-1) of human serum albumin (HSA) and 0.25-13 microg ml(-1) of human immunoglobulin G (IgG) can be determined, and the detection limits, calculated as three times the standard deviation of nine blank measurements, for BSA, HAS and IgG were 51, 48 and 57 microg l(-1), respectively. Moreover, the method shows almost no protein-to-protein variability and 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 the total protein in human serum and saliva samples. Mechanism studies indicated that PR can bind to BSA depending mainly on electrostatic forces, and this interaction can encourage the J-aggregation of PR, which results in enhanced Rayleigh light-scattering in the PR-protein system.

The synthesis and application of 1-( o-nitrophenyl)-3-(2-thiazolyl)triazene for the determination of palladium(II) by the resonance enhanced Rayleigh light-scattering technique

The resonance Rayleigh light-scattering (RRLS) signal of a new triazene reagent; 1-( o-nitrophenyl)-3-(2-thiazolyl)triazene ( o-NPTT), was firstly synthesized and characterized in this paper at 500–600 nm wavelength range and can be enhanced remarkably by Pd 2+. According to this phenomenon, a new method was developed for the determination of Pd 2+ by the RRLS technique in the presence of Tween-80. The calibration graph showed good linearity over a concentration range of 5.0–700 μg l −1 with a detection limit of 1.0 μg l −1. There are almost no foreign ions interfered in the determination at a more than fivefold concentration of Pd 2+. The method is relatively sensitive, of good selectivity and has been successfully used for the determination of trace palladium in the slag of fertilizer factories and catalyst samples.