Study On The New Methods For The Determination Of Some Medicaments With Gold Nanoparticle Probe By Resonance Rayleigh Scattering

Resonance Rayleigh scattering (RRS) and Resonance Nonlinear scattering (RNLS) are new analytical technique developed in 1990s. For its remarkable characteristics of high sensitivity, simplicity and fair selectivity, it attracts more attention and has been applied widely to the study and determination of biological macromolecules such as nucleic acids and proteins and some inorganic ions. Gold nanopartical show the potential applied value because of their especial physical and chemical characteristics. At present, the analytical applications for gold nanopartical are as optical probes or as electrochemical sensors afer chemical modification. However, there is rarely report that RRS method is used to the determinate of Pharmaceuticals with unmodified gold nanoparticle probes. In this work, we investigated RRS and RNLS spectral characteristics of the interaction of gold nanoparticle with vitamin Bi, tetracycline antibiotics, sildenafil, promazine hydrochloride and chlorpromazine hydrochloride. The spectral characteristics, the optimum conditions of the reactions, the affecting factors, the properties of analytical chemistry and their analytical applications have been studied.1. Gold nanoparticle-VB₁ system 1.1 RRS methodIn pH 3.0-5.0 weak acid medium, gold nanoparticle with the diameter of about 12 run appears a certain resonance Rayleigh scattering (RRS), but vitamin B₁ (VB₁) can only produce very weak RRS. When both of them react with each other to form a binding product with bigger volume, the diameter of which increase to about 14 nm from 12 run, the RRSintensity can be enhanced greatly and a new RRS spectrum can be observed. The maximum RRS peak is at 368 nm and there are three scattering peaks that are at 284 nm, 440 nm and 495 nm, respectively. In this work, 495 nm is selected for the measurement wavelength. The relative RRS intensity (A/rrs) is directly proportional to the concentration of VB₁ in the rangeof 0².8×l0^-7 molL^-1. The method has high sensitivity and the detection limit for VB₁ is0.91 ngmL^-1 at a signal-to-noise ratio of 3. The RRS spectral characteristics, optimum conditions for the reaction, the influencing factors were investigated. The effect of coexisting substances on the determination of VB₁ has been tested and the results showed that this method had good selectivity. Therefore, the proposed method is successfully used to determine VB₁ in tablet and injection by RRS with gold nanoparticle probe. 1.2 Spectrophotometric methodWhen gold nanopartical react with VB₁ to form a binding product, the color of the gold nanoparticle solution changes to blue from bright red. Before reaction, there is a plasmon band that is characteristics of gold nanoparticle and VBt has no absorption peak in range of visible region. After reaction, the peak of 518 nm shifts to 528 nm and the value of A reduces, in addition, there is a maximum absorption peak located at 668 nm, which is the characteristic peak of the binding product. The method has high sensitivity and the emax is 1.1 X106 L-mor'-cm"1. The AA value is directly proportional to the concentration of VBi in the range of0².8xl0'7 mol-L'1. The absorption spectral characteristics, optimum conditions for thereaction, the influencing factors were investigated. The effect of coexisting substances on the determination of VBi has been tested and the results show that this method has good selectivity. Therefore, a spectrophotometric method is successfully used to determine VBi in tablet and injection with gold nanoparticle probe has been proposed. 2. Gold nanoparticle- tetracycline antibiotic systemsIn acidic sodium citrate-hydrochloric acid buffer solution, gold nanoparticle interact with chlortetracycline(CTC), tetracycline(TC) and oxytertramycine(OTC) to form the aggregates of bigger volume by the electrostatic attraction and hydrophobic interaction. Take example for CTC, the diameter of aggregation is increased from 12 nm to 16 nm; therefore, the RRS intensity can be greatly enhanced. It can be found that the gold nanoparticle-tetracyclineantibiotic systems have the similar RRS spectra and the main RRS peaks are located at 287 nm, 368 nm and 498 nm. In this work, 498 nm is selected for the measurement wavelength. The concentrations of the tetracycline antibiotic are directly proportional to the relative RRS intensity (AIrrs) in a certain range. The linear ranges of the different systems are 0.2-0.8 Hg/mL for CTC, 0.5-2.0 ug/mL for OTC, 0.2-0.8 ug/mL for TC. So the methods for the determination of tetracycline antibiotics by RRS with gold nanoparticle probe were proposed. Among these systems the gold nanoparticle-CTC system has the highest sensitivity and the detection (3a) limit is 14.1 ng/mL. The detection limits of other tetracycline antibiotic drugs are 39.4 ng/mL for OTC and 17.2 ng/mL for TC, respectively. The RRS spectral characteristics, optimum conditions for the reactions, the influencing factors were researched. Take gold nanoparticle-CTC system for example, the effects of the coexistent substances are investigated, it is found that amino acid, most non-metal ions and glucose do not interfere except small tolerance of heavy metal ions, so the method has a good selectivity. It is applied to determination of amount of CTC in synthetic samples with satisfactory results. 3. Gold nanoparticles-Sildenafil systemIn pH 3.0 BR buffer solution, gold nanoparticle with the diameter of about 12 nm appears a certain resonance Rayleigh scattering (RRS) intensity, but sildenafil can only produce very weak RRS intensity. When both of them react with each other to form a binding product with bigger volume, the diameter of which increase to about 15 nm, the RRS intensity can be enhanced greatly and a new RRS spectrum can be observed. There is a peak band between 280 nm and 368 nm.The maximum RRS peak is at 368 nm and there are some other obvious scattering peaks that are at 284 nm, 440 nm and 495 nm, respectively. In this work, 495 nm is selected for the measurement wavelength. The relative RRS intensity (A/rrs) is directly proportional to the concentration of sildenafil in the range of 0-0.14 (ig/mL. The method has high sensitivity and the detection limit (3ct) for sildenafil is 3.82 ng/mL. The RRS spectral characteristics, optimum conditions for the reactions, the influencing factors were researched. The effect of coexisting substances on the determination of sildenafil has been investigated and the results show that this method has good selectivity. It is applied to determination of amount of sildenafil in synthetic samples with satisfactory results.