Solid Substrate-room Temperature Phosphorimetry Research Articles

Synchronous Multi-sits Determination of H2O2 in Vertical Water Based on Phosphor TiO2/SiO2 Nanocomposite.

A promising strategy for trace analysis of hydrogen peroxide (H2O2) in natural water was established based on solid substrate room temperature phosphorimetry. The use of TiO2/SiO2 composite material as a phosphor for H2O2 detection was investigated. TiO2/SiO2 nanoparticle material was manufactured into a test kit for synchronous multilevel sampling test in the water sample reservoir. The proposed TiO2/SiO2 test kit displayed a wide linear response to H2O2 concentrations ranging from 1.0 × 10(-6) to 1.0 × 10(-1) M with a detection limit of 4.6 × 10(-7) M. When the concentration of other species was 100 times of 1.0 × 10(-4) M H2O2, the proposed test kit exhibited good selectivity toward the coexistence of 20 foreign ions. Satisfactory agreement between the proposed kit and spectrophotometric method was obtained, which demonstrated the possibility of its further development into a promising commercial phosphorescence sensor.

A highly sensitive solid substrate room temperature phosphorimetry for carbaryl detection based on its activating effect on NaIO4 oxidizing fluorescein.

Fluorescein (HFin) could emit strong and stable room temperature phosphorescence (RTP) signal on polyamide membrane (PAM) using Pb(2+) as the ion perturber. Carbaryl could activate effect on NaIO4 oxidating HFin, which caused the RTP signal of the system to quench sharply. The phosphorescence intensity (ΔI p) of activating system higher 3.3 times (119.4/36.0) than that of non-activating system, and is directly proportional to the content of carbaryl. Thus, an activating solid substrate room temperature phosphorimetry (SSRTP) for carbaryl detection has been established. This sensitive (the limit of quantification (LOQ) was 2.0 × 10(-13)gmL(-1)), selective, simple and rapid method has been applied to determine trace carbaryl in water samples with the results consisting with those obtained by fluorimetry, showing its high accuracy. The apparent activation energy (E) and rate constant (k) of this activating reaction were 20.77kJmol(-1) and 1.85 × 10(-4)s(-1), respectively. Meanwhile, the mechanism of activating SSRTP for carbaryl detection was also discussed using infrared spectra (IR).

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.

Fullerol-fluorescein isothiocyanate-concanavalin agglutinin phosphorescent sensor for the detection of alpha-fetoprotein and forecast of human diseases

Based on the reaction of the active –OH group in fullerol (F) with the dissociated –COOH group in fluorescein isothiocyanate (FITC) to form an F-FITC and the enhanced effect of N, N-dimethylaniline (DMA) on phosphorescence signal of F-FITC, a new phosphorescent labeling reagent (DMA-F-FITC) was developed. What’s more, a phosphorescent sensor for the determination of alpha-fetoprotein variant (AFP-V) has been designed via the coupling technique of the high sensitivity for affinity adsorption–solid substrate-room temperature phosphorimetry (AA-SS-RTP) with the strong specificity reaction between DMA-F-FITC-Con A and AFP-V. The DMA-F-FITC increased the number of luminescent molecules in the biological target which improved the sensitivity of phosphorescent sensor. The proposed sensor was responsive, simple, selective and sensitive, and it has been applied to the determination of trace AFP-V in human serum and the forecast of human diseases using phosphorescence emission wavelength of F or FITC, with the results agreed well with those obtained by enzyme-linked immunoassay (ELISA). Meanwhile, the mechanisms for the labeling reaction and the sensing detection of AFP-V were discussed.

A Novel Solid Substrate Room Temperature Phosphorimetry for the Determination of Trace Cytochrome C and Forecast of Human Diseases

The reaction between fullerenol (F-ol) and cytochrome C (Cyt C) could be carried out to form a nonphosphorescence compound using tween-80 as photosensitizer which causes the sharp quenching of room temperature phosphorescence (RTP) of F-ol. Bearing this in mind, a novel solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace Cyt C has been proposed in this study. Under the optimum conditions, the linear range of this method is 1.0×10-16 –2.4×10-14 g mL-1, which is directly proportional to ΔIp of Cyt C-F-ol–tween-80 system, and the detection limit (DL) is 3.0×10−17 g mL-1. It has been applied to the determination of Cyt C in human serum and forecast of diseases, and the result matches with the enzyme-linked fluorescence immunoassay (ELISA). Meanwhile, the reaction mechanism of SSRTP for the determination of Cyt C and the enhancing effect of tween-80 on RTP of F-ol were also discussed.

Ultra-sensitive complex as phosphorescence probe for the determination of trace protein

β-CD-HMTA-L-Tyr complex, formed in the host guest inclusion reaction carried out between host molecule β-cyclodextrin (β-CD) in β-CD-HMTA (HMTA is methenamine) and guest molecule L-tryptophan (L-Tyr), possessing the characteristic of room temperature phosphorescence (RTP). Bovine serum albumin (BSA) reacted with L-Tyr to form a complex of cage structure bringing in the sharply RTP signal quenching of L-Tyr. Based on the above facts, a new ultra-sensitive solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace protein has been established using β-CD-HMTA-L-Tyr complex as a phosphorescence probe. Under the optimum conditions, the linear range of this method was 0.0040–0.56agspot−1 with a detection limit (D.L.) as 0.92zgspot−1, and the regression equations of working curve was ΔIp=0.8239+162.5 mBSA (agspot−1, n=8) with the correlation coefficient (r) of 0.9994. The relatively standard deviation (RSD) and the recovery of SSRTP were 4.8–3.3% and 96.7–102%, respectively, indicating that this method had good repeatability. The proposed phosphorescence probe has been applied in the detection of protein in real samples and the results agreed well with those obtained with SSRTP using methylene blue-sodium tetraphenylborate as phosphorescence probe. Meanwhile, the reaction mechanism for the determination of trace protein with β-CD-HMTA-L-Tyr complex as phosphorescence probe has been discussed.

Catalytic solid substrate–room temperature phosphorimetry for the determination of residual perphenazine based on the electronic effect of rhodamine 6G

The rhodamine 6G(+) -perphenazine (Rhod 6G(+) -PPH) compound is formed in the ester-exchange reaction between -OH of PPH and -COOC2 H5 of Rhod 6G(+) . PPH was oxidized to a red compound (PPH') in the presence of K2 S2 O8 . Interestingly, the room temperature phosphorescence (RTP) of Rhod 6G(+) was quenched because the -OH of PPH' reacted with -COOC2 H5 of Rhod 6G(+) -PPH to form Rhod 6G(+) -PPH' and PPH, which decreased the π-electron density (δ) of the carbon atom in the Rhod 6G(+) -PPH' conjugated system and enhanced the nonradiation energy loss of the excited Rhod 6G(+) of the triplet state. The PPH content was directly proportional to the ΔIp of the system. Thus, a new catalytic solid-substrate room temperature phosphorimetry (SSRTP) method was established for the determination of PPH. The method had high sensitivity (the limit of detection was 0.019 fg/spot, corresponding to a concentration of 4.8 × 10(-14) g/mL; the sampling quantity was 0.40 μL/spot), good selectivity, convenience and speed. The analytical results were in accordance with those of high-performance liquid chromatography (HPLC). The structures of Rhod 6G(+) , PPH and Rhod 6G(+) -PPH were characterized by infrared spectra. The reaction mechanism by which PPH was determined is discussed.

Coupling technique of self-ordered ring and phosphorimetry for the determination of alkaline phosphatase and diseases prediction

Rhodamine S could emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM) in the presence of heavy atom perturber Pb2+. When Rhodamine S-piperidine solution was dropped on PAM, the red (Rhod.S)n-P-SOR (Rhod.S, (Rhod.S)n, P and SOR refer to alizarin red S, multiple Rhod.S molecules, piperidine and self-ordered ring, respectively) formed on PAM, leading to the enhancement of room temperature phosphorimetry (RTP) intensity (Ip, 117.2) of (Rhod.S)n-P-SOR system, which was 2.4 times higher than that without SOR (Ip, 48.1). Wheat germ agglutinin (WGA) was labelled with (Rhod.S)n-P-SOR by the –NH– of Rhod.S reacting with the –COOH of WGA to form WGA-(Rhod.S)n-P-SOR. The formation of WGA-AP-WGA-(Rhod.S)n-P-SOR in the affinity adsorption (AA) reaction carried out between the –COOH of WGA in WGA-(Rhod.S)n-P-SOR and the –NH2 of alkaline phosphatase (AP) caused the RTP intensity (ΔIp) of the WGA-AP-WGA-(Rhod.S)n-P-SOR system 7.8 times larger than that without (Rhod.S)n-P-SOR. Therefore, the coupling technique of SOR and solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace AP has been established. This method possessed good selectivity, high sensitivity (Detection limit (L.D) was 3.4×10−16gmL−1) and accuracy, and it has been applied to the determination of trace AP in human serum and the forecast of human diseases, and the results agreed well with those obtained by enzyme-linked immunoassay (ELISA). Besides, the mechanism of the coupling technique for the determination of AP was discussed.

Highly Sensitive Detection of Residual Chlorpromazine Hydrochloride with Solid Substrate Room Temperature Phosphorimetry

Under the condition of 60°C and 20min at pH 6.12, chlorpromazine hydrochloride (CPZ) could react with fluorescein isothiocyanate (FITC) to produce FITC-CPZ, which increased the π-electron density (δ) of carbon atom in FITC conjugated system and the room temperature phosphorescence (RTP) intensity of FITC. Thus, a new solid substrate room temperature phosphorimetry (SSRTP) for the determination of residual CPZ was established. The regression equation of working curve was ΔI (p) = 4.254 + 7.906 m(CPZ) (ag spot(-1)) with the correlation coefficient (r) of 0.9990 in the range of 0.036-9.6 ag spot(-1) (corresponding concentration: 0.090-24fgml(-1), sample volume: 0.40μl spot(-1)), and the detection limit (LD) was 0.018 ag spot(-1) (corresponding concentration: 4.5 × 10(-17)gml(-1)). This method with wide linear range and high sensitivity was not only used to diagnose human disease based on the correlation between the residual quantity and lethal dose of CPZ in human serum, but also used to determine residual CPZ in biological samples with the results consisting with those obtained by gas chromatography (GC), showing good accuracy. The constituent of FITC-CPZ was analyzed by GC-MS (mass spectrometry) and the reaction mechanism of SSRTP for the determination of trace CPZ was also discussed.

A highly sensitive coupling technique for the determination of trace quercetin based on solid substrate room temperature phosphorimetry and poly (vinyl alcohol) complex imprinting

Al3+ could react with quercetin (Q) to form [AlQ]3+ complex which could be used as a template for the preparation of poly (vinyl alcohol)–[AlQ]3+ complex imprinting (PVA-C-I). The [AlQ]3+ not only had good matching ability and selectivity with the cavity of PVA-C-I, but also could react with the fluorescein isothiocyanate anion (FITC−) on the outside of cavity by electrostatic interaction to form ion-association complex [AlQ]3+·[(FITC)−]3. The ion-association complex could emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM) and the ΔIp of the system had linear relationship with the content of Q, showing the highly selective identification of PVA-C-I to Q. Thus, a new coupling technique for the determination of trace Q based on solid substrate room temperature phosphorimetry and poly (vinyl alcohol) complex imprinting (PVA-C-I-SSRTP) was established. The linear range and limit of detection (LOD) of this method were 0.010–2.0 (×10−12gmL−1) and 2.0×10−14gmL−1, respectively, showing wide linear range and high sensitivity of PVA-C-I-SSRTP. This method was used to determine the content of Q in waste water, and the results are consistent with those by spectrofluorimetry. Meanwhile, the mechanism for the determination of Q using PVA-C-I-SSRTP was also discussed.

Catalytic solid substrate–room‐temperature phosphorimetry detection for trace cadmium with Cd2+–3.5‐generation polyamidoamine dendrimer–Tween‐80 complex

3.5-Generation polyamidoamine dendrimers (3.5-G-D) emitted strong and stable room-temperature phosphorescence (RTP) on filter paper when Pb2+ was used as a heavy atom perturber. The RTP signal of 3.5-G-D was sharply enhanced upon the formation of 3.5-G-D-Tween-80 micelle compound. The complex Cd2+ -3.5-G-D-Tween-80, generated in the coordination reaction between Cd2+ and the tertiary amidocyanogen on the outer layer of 3.5-G-D in 3.5-G-D-Tween-80 micelle compound, could catalyze KBrO3 to oxidize 3.5-G-D in 3.5-G-D-Tween-80, which caused the sharp quenching of the RTP signal of the system. The phosphorescence intensity change (ΔI(p) ) of the system had a linear relationship with the content of Cd2+. Thus a new catalytic solid substrate-room-temperature phosphorimetry (SS-RTP) for the determination of trace cadmium has been established. This highly selective and sensitive method has been applied to determine trace cadmium in biological samples with a limit of detection (LD) of 1.2 ag per spot (when the sample volume was 0.4 μL per spot, the corresponding concentration was 3.0 × 10(-15) g mL(-1) ), the results agreeing with those obtained by atomic absorption spectrometry. The mechanism of catalytic SS-RTP for the determination of trace cadmium was also discussed.

Catalytic solid substrate room temperature phosphorimetry for the determination of trace rhamnose based on its condensation reaction with calcein

Calcein (R) could not only emit strong and stable room temperature phosphorescence (RTP) on filter paper using I − as perturber, but also could be oxidized by H 2O 2 to form a non-phosphorescence compound (R′), resulting in the quenching of RTP signal of R. Moreover, the ortho-hydrogen of phenolic hydroxyl in R took condensation reaction with rhamnose (Rha) to produce non-phosphorescence compound (R–Rha) causing the RTP signal of R to further quench, and R–Rha was oxidized by H 2O 2 to form R′ and Rha, bringing about the sharp RTP signal quenching of R. Thus, a new solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace Rha based on its strong catalytic effect on H 2O 2 oxidizing R has been established, with the detection limit (LD) of 7.8 zg spot −1 (corresponding concentration: 2.0 × 10 −17 g ml −1, sample volume: 0.40 μl spot −1). This method has been applied to determine trace Rha in cigarettes and jujubes, with the results coinciding well with those determined by a high performance liquid chromatography (HPLC). The component of R–Rha also was analyzed by means of HPLC, mass spectrometer and nuclear magnetic resonance (NMR) measurements. The mechanism of catalytic SSRTP for the determination of trace Rha was discussed.

Determination of trace carvedilol by solid substrate–room temperature phosphorimetry, based on its activating effect on hypochlorite‐oxidizing amaranth using sodium dodecyl benzene sulphonate as sensitizer

This work proposes a simple and sensitive solid substrate-room temperature phosphorimetry (SS-RTP) for the selective determination of carvedilol (CV). The method is based on the sensitizing effect of sodium dodecyl benzene sulphonate (SDBS) on CV to activate the oxidation between NaClO and amaranth, resulting in the intense quenching of room temperature phosphorescence (RTP) of the system. Compared with non-SDBS system, the reduction of phosphorescence intensity (ΔI(p)) with SDBS is 16.5 times higher and is directly proportional to the content of CV, covering a wide range 0.080-16.00 fg/spot. The regression equation of the working curve can be expressed as ΔI(p) = 0.7780 + 7.057 m(CV) (fg/spot) (correlation coefficient (r) = 0.9976, n = 8), with a detection limit (LD) of 0.020 fg/spot (corresponding concentration is 5.1 × 10(-14) g/mL, sample volume is 0.40 μL/spot). This sensitive method has also been applied to determine trace CV in human plasma and the results agreed with synchronous fluorimetry (SF). The activation energy (E) and rate constant (k) of this activating reaction were 69.04 kJ/mol and 3.580 × 10(-4) s(-1), respectively. The reaction mechanism is also discussed.

Strong Luminescence Catalytic Solid Substrate Room Temperature Phosphorescence for the Determination of Trace Copper

AbstractUnder the conditions of reacting at 100°C for 8 min and irradiating with the infrared light for 15 min, methylene blue (MEB) could emit weak room temperature phosphorescence (RTP) on the cellulose acetate membrane (CAM) using Pb2+ as the ion perturber in the NH3‐NH4Cl (pH=9.80) solution. MEB was oxidized by H2O2, which caused the RTP of the system to enhance. Cu2+ could catalyze the reaction of H2O2 oxidizing MEB, which caused the RTP of the system to enhance sharply. The ΔIp (Ip0−Ip, the Ip0 and Ip were RTP intensity of the blank reagent and RTP intensity of the test reagent, respectively) of the catalytic system was 133.6, which was 4.1 times larger than that without infrared light irradiation (33.1). Its ΔIp was proportional to the content of Cu2+. Thus, a new catalytic solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace copper has been established. The limit of quantization (LOQ) of this method was 0.12 ag·spot−1 (sample volume: 0.40 µL·spot−1, corresponding concentration: 3.0×10−16 g·mL−1), showing high sensitivity. This method not only has been successfully applied to the determination of trace copper in the tobacco, tea and human serum, but also could predict human diseases. The catalytic reaction was first order reaction, whose activation energy (E) was 18.17 kJ·mol−1 and rate constant (k) was 3.4×10−4 s−1. At the same time, the mechanism of catalytic SSRTP for the determination of trace copper was discussed.

Determination of Trace Deoxyribonucleic Acid by Using Fluorescein Isothiocyanate-Phenosafranine as a Double-Luminescent Phosphorescence Probe

Using Pb2+ as ion perturber, phenosafranine (PF) and fluorescein isothiocyanate (FITC) could emit strong and stable room temperature phosphorescence (RTP) signal on the filter paper, respectively. When they were mixed, the phenomenon that the RTP signal of PF and FITC enhanced significantly was found. And 1.12 ag DNA spot−1 (sample volume was 0.40 μL, corresponding concentration was 2.8 × 10–15 g mL–1) could cause the RTP signal of both PF and FITC to enhance sharply. The content of DNA was proportional to the ΔI p of PF and FITC in the system at 634 and 659 nm. Thus, a new solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace DNA was established by using FITC-PF as double-luminescent phosphorescence probe. The detection limit (LD) of this method calculated by 3Sb/k was 14 zg DNA spot–1 for PF and 18 zg DNA spot–1 for FITC, respectively, showing high sensitivity. It has been applied to the determination of trace DNA in practical samples and the analysis results were in accordance with those of fluorescence probe. The reaction mechanism of SSRTP for the determination of trace DNA was also discussed.

A New Fluorescein Isothiocyanate‐Piperidine Self‐ordered Ring Phosphorescent Probe for the Determination of Trace Protein

AbstractThe COOH in fluorescein isothiocyanate (FITC) reacted with NH in piperidine (P) to form FITC‐P on the center of indentation of polyamide membrane (PAM) when drying for 2 min at (92±1)°C. Then, the FITC‐P diffused outward from the indentation center and formed the round SOR‐P‐FITC (containing the FITC‐P self‐ordered rings). Thus, multi‐FITC accumulated on SOR‐P‐FITC, leading to the enhancement of RTP signal on bio‐target, whose Ip increased 2.0 times compared with non‐generated SOR. When bovine serum albumin (BSA) was added to the center of SOR‐P‐FITC, NCS of FITC in SOR‐P‐FITC reacted with NH2 of BSA to form SOR‐P‐FITC‐BSA, which caused the RTP signal of FITC to enhance sharply. The ΔIp of the system was 3.4 times higher than that without β‐CD and 4.0 times higher than that without SOR‐P‐FITC formed. Its ΔIp was linear to the content of BSA. Therefore, a new solid substrate‐room temperature phosphorimetry (SS‐RTP) for the determination of trace protein was established using SOR‐P‐FITC as a phosphorescent probe. Under the optimum condition, the linear range of this method was 0.040–16.0 ag·spot−1 with a detection limit (LD) of 8.5 zg·spot−1 (0.40 µL sample solution per spot, the corresponding concentration was 2.1×10−17 g·mL−1), and the regression equation of working curve was ΔIp=3.848+4.240mBSA (ag·spot‐1), n=6, correlation coefficient (r) was 0.9993. This method with high sensitivity had been applied to determining the content of trace protein in the water samples, and the results coincided well with those obtained with pyrocatechol violet‐Mo(VI) method (P.V.M.M.). At the same time, the mechanism of SS‐RTP using SOR‐P‐FITC as a phosphorescent probe (SOR‐P‐FITC‐SS‐RTP) was discussed.

Fullerol–fluorescein isothiocyanate phosphorescent labeling reagent for the determination of glucose and alkaline phosphatase

The active –OH group in fullerol (F-ol) could react with the dissociated –COOH group in fluorescein isothiocyanate (FITC) to form F-ol–(FITC) n , which could emit room temperature phosphorescence (RTP) signal of F-ol and FITC on acetate cellulose membrane (ACM), respectively. Their RTP signals were enhanced by N,N-dimethylaniline (DMA). The labeling reaction between the –NCS group of FITC in DMA–F-ol–(FITC) n and the –NH 2 group in wheat germ agglutinin (WGA) produced DMA–F-ol–(FITC) n –WGA, which could further take affinity adsorption (AA) reaction with bioactive substances (BS), such as glucose and alkaline phosphatase (AP), to produce DMA–F-ol–(FITC) n –WGA–BS. Both of these two products could maintain the good RTP characteristics of F-ol and FITC. Based on the facts above, a new phosphorescent labeling reagent, DMA–F-ol–FITC, was developed, and a new affinity adsorption solid substrate room temperature phosphorimetry (AASSRTP) for the determination of BS was established. This method was applied to the determination of BS in human serum and the diagnosis of diseases, with the results agreeing very well with those of enzyme-linked immunosorbent assay (ELISA). The mechanism of DMA–F-ol–(FITC) n labeling of WGA and AASSRTP for the determination of BS is discussed.

A New Phosphorimetry for the Determination of Trace Alkaline Phosphatase Using Multi-wall Carbon Nanotubes and Its Diagnosis of Human Diseases

Multi-wall carbon nanotubes (MWNTs) could be modified as water soluble MWNTs (it was called as MWNTs-A and MWNTs-B) by chemical methods. MWNTs-A and MWNTs-B could emit room temperature phosphorescence (RTP) signal on the surface of nitrocellulose membrane (NCM). A new solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace alkaline phosphatase (ALP) was established based on the signal magnification effect of tween-80 and ALP on MWNTs-B's RTP intensity and the linear relationship between the content of ALP and the DeltaI(P) of the system. The linear range of this method was 0.0020-0.80 (fg spot(-1), sample volume: 0.40 microl spot(-1)), the regression equation of working curve was DeltaI(P) = 0.8170 + 96.84m(ALP) (fg spot(-1)), correlation coefficient (r) was 0.9986. This method had high sensitivity (detection limit (LD): 1.4 ag spot(-1)), good selectivity (Er < or = +/- 5 in-care-of, coexistence species were of no interference), high precision (RSDs were 4.4%-1.2%) and accuracy. It was applied to the determination of trace ALP in human serum and the diagnosis of human diseases. The results were tallied with those of enzyme-linked immunosorbent assay (ELISA). The mechanism of new SS-RTP for the determination of trace ALP was discussed, which laid the theory foundation for the analytical application of MWNTs in life science.

Sensitive Phosphorimetric Determination of Bumetanide in Human Urine with Its Inhibition Effect on the Formation of [Fe-morin] 3+ Complex

A novel solid substrate-room temperature phosphorimetry (SS-RTP) was developed for determination of bumetanide (BMTN). It was validated by determining selectivity, linearity, accuracy, precision, and signal to noise ratio (S/N) for analysis. And all the experiments presented in this work were based on that BMTN inhibited the formation of [Fe-morin](3+) ([FeR](3+)) complex by the reaction between Fe(3+) and R, which led to severe quenching of room temperature phosphorescence (RTP) signal. The rate constant of the reaction (k) was 2.44 x 10(-4) s(-1), the activation energy (E) was 21.39 kJ mol(-1). Detection limit of this method (LD, 5.0 ag spot(-1), corresponding concentration was 1.2 x 10(-14) g mL(-1)) was evaluated and compared with other methods, indicating better sensitivity for BMTN determination using this technique. And due to the high sensitivity of the method, it has been successfully applied to determine BMTN in human urine samples. The linear range was from 0.040 pg mL(-1) to 4.0 pg mL(-1), allowing wide determined range of BMTN. Meanwhile, the mechanism of this method was also discussed.

8-Quinolineboronic acid as a potential phosphorescent molecular switch for the determination of alpha-fetoprotein variant for the prediction of primary hepatocellular carcinoma

8-Quinolineboronic acid phosphorescent molecular switch (8-QBA-PMS) in the "off" state emitted weak room temperature phosphorescence (RTP) of 8-QBA on the acetylcellulose membrane (ACM) with the perturbation of Pb(2+). When 8-QBA-PMS was used to label concanavalin agglutinin (Con A) to form 8-QBA-PMS-Con A based on the reaction between -OH of 8-QBA-PMS and -COOH of Con A, 8-QBA-PMS turned "on" automatically due to its structure change, and RTP of the system increased 2.7 times. Besides, -NH(2) of 8-QBA-PMS-Con A could carry out affinity adsorption (AA) reaction with the -COOH of alpha-fetoprotein variant (AFP-V) to form the product Con A-AFP-V-Con A-8-QBA-PMS containing -NH-CO- bond, causing the RTP of the system to further increase. Moreover, the amount of AFP-V was linear to the DeltaI(p) of the system in the range of 0.012-2.40 (fg spot(-1)). Thus, a new affinity sensitive adsorption solid substrate room temperature phosphorimetry using 8-QBA-PMS as labelling reagent (8-QBA-PMS-AASSRTP) for the determination of AFP-V was proposed with the detection limit (LD) of 9 x 10(-15) g mL(-1). It had been used to determine AFP-V in human serum with the results agreeing with enzyme-link immunoassay (ELISA), showing promise for the prediction of PHC due to the intimate association between AFP-V and primary hepatocellular carcinoma (PHC). The mechanism of the promethod was also discussed.