Metal Nanoclusters Involved Flow Injection Chemiluminescence And Their Analysis Application

Chemiluminescence analysis method is a kind of molecular luminescence spectrometry, with a high sensitivity and a wide linear range, the instrument is simple, and there is no background interference caused by the external light source. Flow injection chemiluminescence(FI-CL) method has been widely used in the fields of inorganic, organic and pharmaceutical analysis. In addition to the advantages of the CL method, FI-CL method has the advantages of rapid analysis and high reproducibility of analytical results. At present, in order to enhance its sensitivity and expand the scope of application of CL, the reaserch of chemiluminescence analysis mainly focused on two points, one is to find new CL reaction system, the other is to combine the existing CL reaction system with newly emerged materials or technology. Nanomaterials are a new type of material between the conventional material and the micro particle, often exhibits specific electrical, magnetic, optical, and chemical properties. In recent years, researchers have introduced nanomaterials into the chemiluminescence methods. The nanomaterials enhance the weak chemiluminescence signal by the role of catalytic agent, reducing agent, carrier and energy receptor. Metal nanoclusters consisting of 101~102 atoms, its particle size is generally less than 2 nm. Metalclusters have a special discrete energy level and molecular size, showing a strong photoluminescence, excellent optical stability, good biocompatibility and sub nanometer particle size, are a potential material, and has been widely used in the fields of fluorescence, biological analysis and so on, but its application in the field of chemical luminescence is less. This paper is divided into two parts:The first part briefly reviewed the applications of metalclusters in analytical chemistry in recent years and focused on the metal nanoparticles(including metal nanoparticles) involved liquid phase chemiluminescence system and its application.The second part is a research report. The new material metal nanoparticles were introduced into the ultra weak chemiluminescence system to construct new methods of chemiluminescence of environmental protection and simple. We also introduced the metal nanoclusters to the traditional luminol systems to enhance the sensitivity of the original method, the mechanism and application were also studied. This part consists of three parts as follows:Gold nanocluster-enhanced peroxynitrous acid chemiluminescence method for sensing of nitrite in water samples and the human body.Peroxynitrous acid(ONOOH) produced by online mixing of nitrite and acidified hydrogen peroxide could induce weak chemiluminescence(CL). A stronger chemiluminescence was observed in the presence of gold nanoclusters(Au NCs). This novel CL system was developed as a flow-injection method for the nitrite determination directly and conveniently. This method was achieved in acidic medium, which greatly improved its selectivity. The CL mechanism of the peroxynitrous acid–gold nanocluster system was investigated using CL spectroscopy, UV-visible spectroscopy and radical scavengers. The enhanced CL could be attributed to the catalysis of Au nanoclusters. The proposed method has been applied to determine nitrite in water samples and human urine samples with good accuracy and precision.Chemiluminescence system of luminol-K3Fe(CN)6 catalyzed by copper nanoparticles and its application in pharmaceutical analysisUntil now, it is practically blank state in the study of catalytic activity of metal nanoclusters(NCs) in flow-injection chemiluminescence reaction. In this report we demonstrate that Copper nanoclusters exhibited better chemiluminescence(CL) catalysis activity in luminol-K3Fe(CN)6 system. The enhancement mechanism of Cu QC@BSA on luminol-K3Fe(CN)6 CL system was investigated using the CL spectra, UV-visible spectroscopy, X-ray photoelectron spectroscopy(XPS) and radical scavengers. This CL reaction can be strongly inhibited in the presence of some organic compounds. As a model, the proposed method had been applied for the determination of hydroquinone in tap water samples and dompine in human serum samples with good accuracy and precision.The investigation of the reaction of BSA-gold nanoclusters with potassium permanganate in flow-injection chemiluminescenceThe chemiluminescent reaction induced by BSA-gold nanoclusters(BSA-Au NCs) and KMn O4 was observed for the first time. The effects of the acid medium, concentration of potassium permanganate(KMn O4), Au NCs and the effect of radical scavengers were investigated. CL spectra, UV-visible spectroscopy before and after the CL reaction were also analyzed. A CL mechanism has been speculated that BSA on surface of the Au NCs partly act as a reducing agent, Au0 in the core of BSA-Au NCs may be an enhancer or catalyst and KMn O4 was reduced to the excited state Mn(II)* with the light emission around 640 nm. This system is considered to have potential applications in biological analysis.