Zhen-Bo Liu

Determination of trace glucose and forecast of human diseases by affinity adsorption solid substrate-room temperature phosphorimetry based on triticum vulgaris lectin labeled with dendrimers-porphyrin dual luminescence molecule

In this paper, 3.5-generation polyamidoamine dendrimers (3.5G-D)-porphyrin (P) dual luminescence molecule (3.5G-D-P) was developed as a new phosphorescence-labeling reagent. Meanwhile, the room temperature phosphorescence (RTP) characteristics of 3.5G-D-P and its product of labeling triticum vulgaris lectin (WGA) on the surface of polyamide membrane (PAM) were studied. Results showed that in the presence of heavy atom perturber LiAc, 3.5G-D and P of 3.5G-D-P molecule could emit strong and stable RTP on the PAM. And the Tween-80 would spike thoroughly the phosphorescence signal of 3.5G-D and P; moreover, specific affinity absorption (AA) reaction between the products (Tween-80-3.5G-D-P-WGA) of WGA labeled with Tween-80-3.5G-D-P and glucose (G) was carried out. The products of the AA reaction could keep good RTP characteristics of 3.5G-D and P dual luminescence molecule, and the DeltaI(p) was linear correlation to the content of G. According to the facts above, a new method of affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) for the determination of trace G was established, basing on WGA labeled with Tween-80-3.5G-D-P dual luminescence molecule. The detection limit of this method was 0.13fgspot(-1) (1.7x10(-12)moll(-1), 3.5G-D) and 0.14fgspot(-1) (2.2x10(-12)moll(-1), P). Determination of G in human serum using excitation/emission wavelength of either 3.5G-D or P, the result was coincided with enzyme-linked immunosorbent assay (ELISA). Not only the sensitivity and accuracy of this method were higher, but also the flexibility of AA-SS-RTP was obviously improved and the applicability was wider.

Exploitation of phosphorescent labelling reagent of fullerol-fluorescein isothiocyanate and new method for the determination of trace alkaline phosphatase as well as forecast of human diseases.

A new phosphorescent labelling reagent consisting of fullerol, fluorescein isothiocyanate and N,N-dimethylaniline (F-ol-(FITC)(n)-DMA) was developed. The mode of action is based on the reactivity of the active -OH group in F-ol with the -COOH group of FITC to form an F-ol-(FITC)(n)-DMA complex containing several FITC molecules. F-ol-(FITC)(n)-DMA increased the number of luminescent molecules in the biological target of WGA-AP-WGA-F-ol-(FITC)(n)-DMA (WGA and AP are wheat germ agglutinin and alkaline phosphatase, respectively) which improved the sensitivity using solid substrate room temperature phosphorimetry (SSRTP) detection. The proposed method provided high sensitivity and strong specificity for WGA-AP. The limit of detection (LD) was 0.15 ag AP spot(-1) for F-ol and 0.097 ag AP spot(-1) for FITC in F-ol-(FITC)(n)-DMA, which was lower than the method using single luminescent molecules of F-ol-DMA and FITC-DMA to label WGA (0.20 ag AP spot(-1) for F-ol-DMA and 0.22 ag AP spot(-1) for FITC-DMA). Results for the determination of AP in human serum were in good agreement with those obtained by enzyme-linked immunosorbent assay. The mechanism of F-ol-(FITC)(n)-DMA labelling of WGA was discussed.

Affinity adsorption solid substrate-room temperature phosphorimetry for the determination of alkaline phosphatase

Abstract In the presence of Pb(Ac)2, the silicon dioxide nanoparticle containing rhodamine 6G (R‐SiO2) can emit strong and stable solid substrate‐room temperature phosphorescence (SS‐RTP) signal on the surface of acetyl cellulose membrane (ACM) at λex/λem=482/649 nm. It was found in the research that specific affinity adsorption reaction between triticum vulgare lectin (WGA) (which was labeled with luminescent silicon dioxide nanoparticle) and alkaline phosphatase (AP) can be carried out on the surface of ACM. The product of the reaction can emit stronger SS‐RTP signal. A new method of SS‐RTP for the determination of AP was established, based on an affinity adsorption reaction between AP and WGA labeled with nanoparticles containing rhodanime 6G luminescent molecules. The linear range of this WGA‐AP‐WGA‐R‐SiO2 method is 1.00–360.00 ag AP spot−1 (sample volume: 0.40 µL spot−1, corresponding concentration range: 2.50–900.00 fg mL−1). The regression equation of working curve is ΔIp=16.24+0.8856 mAP (ag spot−1), r=0.9993. Detection limit of this method calculated by 3Sb/k is 0.14 ag spot−1. After 11‐fold replicate measurements, RSD are 3.9% and 3.1% for the systems containing 1.00 and 360.00 ag AP spot−1, respectively. Compared with R‐SiO2‐WGA‐AP method (detection limit: 0.45 ag spot−1, corresponding concentration range: 2.00–320.00 ag spot−1), the sensitivity of WGA‐AP‐WGA‐R‐SiO2 method was obviously improved and the linear range was wider. The sensitivity, accuracy, and precision of this method are high. It has been successfully applied to determine AP in human serum.

Design of an ultra-sensitive gold nanorod colorimetric sensor and its application based on formaldehyde reducing Ag+

Formaldehyde (HCHO) could reduce Ag+ to Ag on the surface of gold nanorods (AuNRs) to form Au core–Ag shell nanorods (Au@AgNRs) in a AuNRs–Ag+–HCHO system, which caused the dielectric function to change, the longitudinal plasmon absorption band (LPAB) of AuNRs to redshift (ΔλLPAB) and the color of the solution to change obviously. Thus, a responsive, simple, sensitive and selective AuNRs colorimetric sensor for the determination of HCHO has been developed based on the linear relationship between ΔλLPAB and the concentration of HCHO. The limit of detection (LOD) of this sensor is 6.3 × 10−11 (g mL−1), which is much lower than that of surface-enhanced Raman spectroscopy (SERS), showing its high sensitivity. Whats more, the sensor has been applied to the detection of HCHO in water samples with the results agreeing well with resonance fluorescence spectrometry, showing its great practicality. Furthermore, the morphological changes of AuNRs and Au@AgNRs were characterized by transmission electron microscopy (TEM) and the sensing mechanism for the detection of HCHO was also discussed.

Design of highly sensitive phosphorescence sensor for determination of procaterol hydrochloride based on inhibition of KClO3 oxidation fluorescein isothiocyanate.

Procaterol hydrochloride (Prh) can inhibit KClO3 oxidation of fluorescein isothiocyanate (FITC) to form a non-phosphorescent compound, which causes room temperature phosphorescence (RTP) of FITC in the system to enhance sharply the linear relationship between ∆Ip and the Prh content. Thus, a rapid response and highly sensitive phosphorescence sensor for the determination of Prh has been developed based on the inhibiting effect of Prh on KClO3 oxidation of FITC. This simple, high sensitivity (detection limit (LD) calculated by 3Sb /k was 0.019 fg/spot, sample volume 0.40 µl, corresponding concentration 4.8 × 10(-14) g ml(-1) ) and selective sensor with a wide linear range (0.080-11.20 g/spot) has been applied to detect Prh in blood samples, and the results were consistent with those obtained by high-performance liquid chromatography (HPLC). Simultaneously, the mechanism of the phosphorescence sensor for the detection of Prh was also investigated using infrared spectroscopy.

Determination of trace α‐fetoprotein variant by affinity adsorption solid substrate‐room temperature phosphorimetry

The 3.5-generation dendrimers (3.5G-D)-porphyrin (P) dual luminescent molecule (3.5G-D-P) was used to label concanavalin agglutinin (Con A); the product of the reaction is 3.5G-D-P-Con A. A new method for the determination of trace AFP-V by affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) was established, based on the room temperature phosphorescence (RTP) property of the product on polyamide membrane (PAM) substrate and the specific affinity adsorption (AA) reaction between 3.5G-D-P-Con A and alpha-fetoprotein variant (AFP-V), which caused the RTP of the system to be sharply enhanced, the DeltaIp was linearly correlated to the content of AFP-V. The sensitivity of the method was obviously high. It could accurately detect the content of AFP-V in serum. The results were tallied well with those obtained by the ELISA method.

Highly Sensitive Fluorescent Probe for Clenbuterol Hydrochloride Detection Based on its Catalytic Oxidation of Eosine Y by NaIO4

A highly sensitive fluorescent probe for clenbuterol hydrochloride (CLB) detection has been first designed based on its catalytic effect on NaIO4 oxidating eosine Y (R). And this environment-friendly, simple, rapid, selective and sensitive fluorescent probe has been utilized to detect CLB in the practical samples with the results consisting with those obtained by GC/MS. The structures of R and CLB were characterized by infrared spectra. The mechanism of the proposed assay for the detection of CLB was also discussed.

Ultra-sensitive solid substrate-room temperature phosphorimetry for colchicine detection based on its catalytic effect on H2O2 oxidation of acridine yellow

A new solid substrate-room temperature phosphorimetry (SS-RTP) method for colchicine (COL) detection has been established based on its strong catalytic effect on H2O2 oxidation of acridine yellow (AY), which sharply quenched the room temperature phosphorimetry (RTP) of AY. This highly sensitive (the limit of quantification (LOQ) was 3.1 × 10−13 g mL−1), accurate and selective SS-RTP has been successfully applied for COL detection in human serum and tea samples with the results efficiently agreeing with the results for high performance liquid chromatography (HPLC); the results were also in agreement with those obtained by ultrafast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS). The activation energy and the reaction rate constant of catalytic reaction were 40.53 kJ mol−1 and 3.97 × 10−4 s−1, respectively. In addition, the reaction mechanism of catalytic SS-RTP for COL detection was also discussed using infrared spectra (IR), nuclear magnetic resonance (NMR) and electron impact mass spectra (EIMS).

Sensitive and rapid biosensor for the determination of rhamnose based on the catalytic effect of the oxidation of calcein by H2O2

We report a new catalytic biosensor for the detection of rhamnose (Rha) based on combining the high sensitivity of a fluorescence method with the high selectivity of a catalytic reaction. The biosensor has the advantages of high sensitivity (limit of detection 1.9 × 10−17 g mL−1) and selectivity; it is non-radioactive, non-invasive and safe to use. The biosensor was used to determine trace amounts of Rha in cigarettes and jujubes and the results were in good agreement with those obtained by high-performance liquid chromatography. Calcein (R)-Rha was also determined by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance. We also report the mechanism used in the catalytic biosensor for the determination of trace amounts of Rha.