1
|
Zhao Q, Wu Q, Ma P, Xu L, Zhang F, Li D, Liu X, Xu S, Sun Y, Song D, Wang X. Selective and sensitive fluorescence detection method for pig IgG based on competitive immunosensing strategy and magnetic bioseparation. Talanta 2018; 195:103-108. [PMID: 30625519 DOI: 10.1016/j.talanta.2018.11.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 11/04/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
Abstract
A novel fluorescence detection method based on competitive immunoassay and magnetic bioseparation technique was developed and applied to the determination of pig immunoglobulin G (IgG) in serum samples. Core-shell structured Fe3O4@SiO2 nanoparticles were synthesized by chemical coprecipitation, followed by functionalization with amino groups and immobilization of pig IgG antibodies. The synthesized Fe3O4@SiO2-antibody nanoparticles were employed as the probe for the competitive immune recognition of the target antigens in samples and the antigens labeled with fluorescein isothiocyanate (FITC). After the magnetic separation of probes binding with these two types of antigens, fluorescence of the free FITC-labeled antigens was measured for the quantification of the target antigens, since the ratio of the FITC-labeled antigens in supernatant before and after the competitive immune recognition depends on the amount of the target antigens in sample, due to the competitive nature of the binding of the antibody for these two types of antigens. Under the optimal conditions, a linear relationship was obtained between the change of fluorescence intensity and the concentration of pig IgG in a range from 0.75 to 23.50 µg L-1, with a detection limit (LOD) of 0.031 µg L-1. With the facile-prepared probes, this fluorescence competitive method can provide a rapid, specific and highly sensitive immunoassay protocol for the determination of target proteins in complex matrix samples.
Collapse
Affiliation(s)
- Qingnan Zhao
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Qiong Wu
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Pinyi Ma
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Longbin Xu
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Fangmei Zhang
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Dan Li
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Xin Liu
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Shaomei Xu
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Ying Sun
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Daqian Song
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China
| | - Xinghua Wang
- College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China.
| |
Collapse
|
2
|
Zhang Y, Yang X, Qian J, Gu X, Zhang J, Liu J, Hu Z. Simultaneous detection of Mycoplasma pneumoniae IgG and IgM using dual-label time resolved fluoroimmunoassay. Anal Biochem 2018; 548:1-6. [PMID: 29462595 DOI: 10.1016/j.ab.2018.02.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 02/05/2018] [Accepted: 02/14/2018] [Indexed: 10/18/2022]
Abstract
Anti-Mycoplasma pneumoniae (MP) IgM and IgG are useful serological markers for detection of MP infection. In this study, a simultaneous quantification of MP IgM and IgG was performed by time-resolved fluoroimmunoassay (TRFIA). The europium-labeled anti-human IgM and samarium-labeled anti-human IgG were used as tracers, and MP IgM and IgG were recognized in serum samples. After dissociating europium and samarium ions from the immune complex, their fluorescence intensity was recorded and used to calculate the concentrations. The linear range and sensitivity of detection were 2-5500 BU/mL and 0.5 BU/mL for IgM, and 1.5-1500 BU/mL and 0.2 BU/mL for IgG, respectively. The intra- and inter-assay coefficients of variation were 5.14% and 8.41% for IgM, and 5.44% and 8.76% for IgG, respectively. The recovery rate was 94.9-106.8% for IgM and 96.1-109.4% for IgG. The correlation rates of serum detection for 38 respiratory infected patients between dual-label TRFIA and ELISA were 0.9294 and 0.9366 for IgM and IgG, respectively. The coincidence rate between passive particle agglutination and TRFIA is 93.3%. Dual-label TRFIA is a sensitive and reliable technique for measuring MP IgM and IgG levels and could be useful for the early diagnosis of MP infection.
Collapse
Affiliation(s)
- Yi Zhang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Xue Yang
- Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu, 214023, China
| | - Jun Qian
- Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu, 214023, China; Wuxi Children's Hospital, Wuxi, Jiangsu, 214023, China
| | - Xiaohong Gu
- Wuxi Children's Hospital, Wuxi, Jiangsu, 214023, China
| | - Jue Zhang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063, China
| | - Jie Liu
- Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu, 214023, China.
| | - Zhigang Hu
- Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu, 214023, China; Wuxi Children's Hospital, Wuxi, Jiangsu, 214023, China.
| |
Collapse
|
3
|
Nesměrák K, Třmínková P. Spectrometric methods for determination of ligand–protein ratio in monoclonal conjugates: a mini review. MONATSHEFTE FUR CHEMIE 2016. [DOI: 10.1007/s00706-016-1747-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
4
|
Liu H, Rong P, Jia H, Yang J, Dong B, Dong Q, Yang C, Hu P, Wang W, Liu H, Liu D. A Wash-Free Homogeneous Colorimetric Immunoassay Method. Am J Cancer Res 2016; 6:54-64. [PMID: 26722373 PMCID: PMC4679354 DOI: 10.7150/thno.13159] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/30/2015] [Indexed: 11/29/2022] Open
Abstract
Rapid and convenient biosensing platforms could be beneficial to timely diagnosis and treatment of diseases in virtually any care settings. Sandwich immunoassays, the most commonly used methods for protein detection, often rely on expensive tags such as enzyme and tedious wash and incubation procedures operated by skilled labor. In this report, we revolutionized traditional sandwich immunoassays by providing a wash-free homogeneous colorimetric immunoassay method without requirement of any separation steps. The proposed strategy was realized by controlling the growth of gold nanoparticles (AuNPs) to mediate the interparticle spacing in the protein-AuNP oligomers. We have demonstrated the successful in vitro detection of cancer biomarker in serum samples from patients with high clinical sensitivity and specificity.
Collapse
|
5
|
A signal-off sandwich photoelectrochemical immunosensor using TiO2 coupled with CdS as the photoactive matrix and copper (II) ion as inhibitor. Biosens Bioelectron 2015; 65:97-102. [DOI: 10.1016/j.bios.2014.10.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/30/2014] [Accepted: 10/08/2014] [Indexed: 11/21/2022]
|
6
|
Hu Z, Li M, Liu J, Yu L, Xue Y, Chen Y. Detection of Hepatitis B Virus Large Surface Protein Using a Time-Resolved Immunofluorometric Assay. J Clin Lab Anal 2014; 29:498-504. [PMID: 25277704 DOI: 10.1002/jcla.21800] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 06/17/2014] [Accepted: 08/07/2014] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND To establish a novel method based on time-resolved immunofluorometric assay (TR-IFMA) with higher sensitivity and a broader detection range for detecting serum hepatitis B virus large surface protein (L protein). METHODS The precision, sensitivity, specificity, coefficient of recovery, and stability of the assay were evaluated and comparison with the classical enzyme-linked immunosorbent assay (ELISA) was also executed. RESULTS The precision, specificity, and sensitivity of the TR-IFMA were clearly better than ELISA. Particularly, the sensitivity was 0.1 ng/ml; moreover, the specificity was 100%, 96%, 92.5%, 96.9%, 97.8%, and 100% in the sera of healthy blood donors, systemic lupus erythematosus (SLE) patients, rheumatoid arthritis (RA) patients, hepatitis C virus (HCV) patients, cytomegalovirus (CMV) infection patients, and pregnant patients, respectively. Meanwhile, we observed that the established TR-IFMA kit has a wider acceptable linear range of 0.63-10,367 ng/ml rather than the regular commercial ELISA kit having range of only 10.12-1095.9 ng/ml. Subsequently, correlation coefficient between the TR-IFMA and ELISA was 0.8009. The intra- and interassay precision rates were less than 5% for three different concentrations. The average recovery rate for L protein was 101.17%. In sum, the established assay kit performed better in terms of stability than the commercial ELISA kit. CONCLUSION The TR-IFMA that we developed for L protein presented a higher sensitivity and wider detecting range than regular commercial ELISA. Therefore, this TR-IFMA has promising value both in the screening of HBV and monitoring of antiviral therapy.
Collapse
Affiliation(s)
- Zhigang Hu
- Department of Laboratory Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Department of Laboratory Medicine, Affiliated Wuxi people's Hospital of Nanjing Medical University, Wuxi, China
| | - Mei Li
- Department of Laboratory Medicine, Affiliated Wuxi people's Hospital of Nanjing Medical University, Wuxi, China
| | - Jie Liu
- Department of Laboratory Medicine, Affiliated Wuxi people's Hospital of Nanjing Medical University, Wuxi, China
| | - Lei Yu
- Department of Laboratory Medicine, Affiliated Wuxi people's Hospital of Nanjing Medical University, Wuxi, China
| | - Yifeng Xue
- Department of Laboratory Medicine, Affiliated Wuxi people's Hospital of Nanjing Medical University, Wuxi, China
| | - Yu Chen
- Department of Laboratory Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| |
Collapse
|
7
|
Yang P, Li X, Wang L, Wu Q, Chen Z, Lin X. Sandwich-type amperometric immunosensor for cancer biomarker based on signal amplification strategy of multiple enzyme-linked antibodies as probes modified with carbon nanotubes and concanavalin A. J Electroanal Chem (Lausanne) 2014. [DOI: 10.1016/j.jelechem.2014.08.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
Chatterjee K, Sarkar S, Jagajjanani Rao K, Paria S. Core/shell nanoparticles in biomedical applications. Adv Colloid Interface Sci 2014; 209:8-39. [PMID: 24491963 DOI: 10.1016/j.cis.2013.12.008] [Citation(s) in RCA: 236] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 12/19/2013] [Accepted: 12/19/2013] [Indexed: 12/21/2022]
Abstract
Nanoparticles have several exciting applications in different areas and biomedial field is not an exception of that because of their exciting performance in bioimaging, targeted drug and gene delivery, sensors, and so on. It has been found that among several classes of nanoparticles core/shell is most promising for different biomedical applications because of several advantages over simple nanoparticles. This review highlights the development of core/shell nanoparticles-based biomedical research during approximately past two decades. Applications of different types of core/shell nanoparticles are classified in terms of five major aspects such as bioimaging, biosensor, targeted drug delivery, DNA/RNA interaction, and targeted gene delivery.
Collapse
|
9
|
Ye Y, Hu Z, Liu J, Chen G, Zhou Y. A new Eu(3+)-labeled method for anticardiolipin antibody IgM. J Clin Lab Anal 2014; 28:335-40. [PMID: 24659029 DOI: 10.1002/jcla.21690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 08/22/2013] [Accepted: 08/30/2013] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND The anticardiolipin antibodies (aCL) test has become a laboratory standard for the clinical diagnosis of antiphospholipid syndrome (APS). To better the quantitative detection of aCL-IgM so as to classify patients correctly and timely as APS positive, we established herein a new immunoassay based on a time-resolved fluoroimmunoassay (TRFIA). METHODS The complex of cardiolipin plus bovine anti-β2 glycoprotein-I was used as antigen fixed on microtiter plates to detect serum aCL-IgM, and Eu(3+) -labeled rabbit antihuman IgM was used as conjugate. The precision, sensitivity, specificity, coefficient of recovery, and stability of the assay were evaluated, and comparison with the traditional, classical enzyme-linked immunosorbent assay (ELISA) was also made. RESULTS The detection limit of the aCL-IgM TRFIA kit we established was 0.1 MPL U/ml, with a wider detectable range than commercial ELISA ones when a strong-positive specimen was diluted from 2,630.9 to 0.08 MPL U/ml. There was a good liner range within 0.16 to 2,630.9 MPL U/ml, whereas it was within 5.14 to 328.86 MPL U/ml when using three commercial ELISA ones. The average intra- and interassay variability was 3.19 and 3.70%, respectively. The mean recovery rate was 101.95%. The clinical diagnostic specificity was 98%. Additionally, the established assay kit presented good characteristics of stability and correlated well with the ELISA, and the correlation coefficient was 0.955. CONCLUSION The aCL-IgM TRFIA provides an approach to a more sensitive and reliable diagnosis of APS. Further validation of its use is required.
Collapse
Affiliation(s)
- Yan Ye
- Department of Clinical Laboratory, Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China
| | | | | | | | | |
Collapse
|
10
|
Du S, Guo Z, Chen B, Sha Y, Jiang X, Li X, Gan N, Wang S. Electrochemiluminescence immunosensor for tumor markers based on biological barcode mode with conductive nanospheres. Biosens Bioelectron 2014; 53:135-41. [DOI: 10.1016/j.bios.2013.09.041] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/19/2013] [Accepted: 09/19/2013] [Indexed: 01/06/2023]
|
11
|
Liu J, Ye Y, Hu Z, Zou Y, Chen G, Yu L. A hypersensitive biotin-avidin-TRFIA for quantitative detection of ANA-Ig(GAM) and its clinical application. J Immunoassay Immunochem 2013; 34:197-207. [PMID: 23537303 DOI: 10.1080/15321819.2012.699495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We demonstrate herein a novel time-resolved fluoroimmunoassay (TRFIA) with high sensitivity and wide range for quantitative detection of ANA-Ig(GAM) antibodies using a biotin-avidin amplification system. The immunoassay was conducted by following procedures for a typical sandwich immunoreactions with cell nucleus form Hela and the Eu(3+)-labeled biotin combined with biotinylated mouse anti-human Ig(GAM) served as the solid nuclear antigen for ANA and the tracer, respectively. The sensitivity, specificity, and stability of the kit were evaluated and comparison with the classical enzyme-linked immunosorbent assay (ELISA) kit was also made. The average intra-assay and interassay CVs detected by the established ANA-Ig(GAM) biotin-avidin-TRFIA were 4.21% and 6.34%, respectively. The lower detection limit was 2.24 U/mL, and the mean recovery rate was 100.74%. The good measurable range of the established biotin-avidin-TRFIA was within 1.95-64,000 U/mL, while it was only within 32.5-4000 U/mL using an ELISA kit. The values determined by the biotin-avidin-TRFIA and ELISA correlated well (R2 = 0.989). The positive rate of healthy volunteers and patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary biliary cirrhosis (PBC), Sjögren's syndrome (SS), scleroderma, and mixed connective tissue disease (MCTD) was 0, 100%, 18.5%, 100%, 37.9%, 90.9%, and 92%, respectively. We conclude that the biotin-avidin-TRFIA we developed gives promise for greater sensitivity and accurate detection for ANA-Ig(GAM) in diagnosing and monitoring autoimmune disorders.
Collapse
Affiliation(s)
- Jie Liu
- Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China
| | | | | | | | | | | |
Collapse
|
12
|
Hu Z, Liu J, Ye Y, Zhou Y, Yu L. DETECTION OF ANTICARDIOLIPIN ANTIBODY IGM BY SM3+-LABELED TIME-RESOLVED FLUOROIMMUNOASSAY. J Immunoassay Immunochem 2013; 34:255-65. [DOI: 10.1080/15321819.2012.709212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
13
|
Zhao H, Chang Y, Liu M, Gao S, Yu H, Quan X. A universal immunosensing strategy based on regulation of the interaction between graphene and graphene quantum dots. Chem Commun (Camb) 2013; 49:234-6. [DOI: 10.1039/c2cc35503e] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
14
|
Ye Y, Hu Z, Liu J, Chen G, Zhou Y, Yu L. Detection of anticardiolipin antibody IgG by time-resolved fluoroimmunoassay. Clin Rheumatol 2012; 31:1339-45. [PMID: 22684164 DOI: 10.1007/s10067-012-2020-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 05/22/2012] [Accepted: 05/30/2012] [Indexed: 11/30/2022]
Abstract
In an effort to improve the quantitative detection of anticardiolipin antibodies (aCL) IgG so as to classify patients correctly as antiphospholipid syndrome (APS) positive, we developed a new immunoassay based on a sandwich time-resolved fluoroimmunoassay (TRFIA) using the complex of cardiolipin plus bovine β(2)GPI as antigen and Eu(3+)-labeled rabbit antihuman IgG as conjugate. The precision, sensitivity, specificity, and stability of the assay were evaluated, and comparison with the classical ELISA was also made. The aCL IgG TRFIA kit we established had a wider detectable range than three commercial ELISA ones from different manufacturers when a specimen was diluted, with strong positive result from 1:12.5 to 1:204,800. The average intra-assay and inter-assay CVs detected by the aCL IgG TRFIA was 3.14 and 3.70 %, respectively. The sensitivity was 0.1 GPL U/ml, and the clinical diagnostic specificity was 98 %. The established assay kit also behaved better in stability than the commercial ELISA ones. Additionally, the immunoassay we established correlated well with the ELISA, and the correlation coefficient was 0.975. We thus conclude that the TRFIA we developed for aCL IgG detection gives promise to a more sensitive and reliable diagnosis of APS and has potential value for large-scale screening programs.
Collapse
Affiliation(s)
- Yan Ye
- Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
| | | | | | | | | | | |
Collapse
|
15
|
Qin G, Zhao S, Huang Y, Jiang J, Ye F. Magnetic bead-sensing-platform-based chemiluminescence resonance energy transfer and its immunoassay application. Anal Chem 2012; 84:2708-12. [PMID: 22339489 DOI: 10.1021/ac202959d] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A competitive immunoassay based on chemiluminescence resonance energy transfer (CRET) on the magnetic beads (MBs) is developed for the detection of human immunoglobulin G (IgG). In this protocol, carboxyl-modified MBs were conjugated with horseradish peroxidase (HRP)-labeled goat antihuman IgG (HRP-anti-IgG) and incubated with a limited amount of fluorescein isothiocyanate (FITC)-labeled human IgG to immobilize the antibody-antigen immune complex on the surface of the MBs, which was further incubated with the target analyte (human IgG) for competitive immunoreaction and separated magnetically to remove the supernatant. The chemiluminescence (CL) buffer (containing luminol and H(2)O(2)) was then added, and the CRET from donor luminol to acceptor FITC in the immunocomplex on the surface of MBs occured immediately. The present protocol was evaluated for the competitive immunoassay of human IgG, and a linear relationship between CL intensity ratio (R = I(425)/I(525)) and human IgG concentration in the range of 0.2-4.0 nM was obtained with a correlation coefficient of 0.9965. The regression equation was expressed as R = 1.9871C + 2.4616, and a detection limit of 2.9 × 10(-11) M was obtained. The present method was successfully applied for the detection of IgG in human serum. The results indicate that the present protocol is quite promising for the application of CRET in immunoassays. It could also be developed for detection of other antigen-antibody immune complexes by using the corresponding antigens and respective antibodies.
Collapse
Affiliation(s)
- Guoxin Qin
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin, China
| | | | | | | | | |
Collapse
|
16
|
Zhang K, Yan HT, Zhou T. Spectrofluorimetric determination of phenylalanine based on fluorescence enhancement of europium ion immobilized with sol-gel method. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 83:155-160. [PMID: 21917509 DOI: 10.1016/j.saa.2011.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 08/05/2011] [Indexed: 05/31/2023]
Abstract
The analysis of phenylalanine (Phe) in serum is widely performed for the screening of newborn phenylketonuria (PKU). In this work, a novel spectrofluorimetric method for the determination of Phe was developed based on the fluorescence enhancement of Ruhemann's purple, the reaction product between Phe and ninhydrin, upon coordination with Eu(3+). A filter paper disc containing immobilized reactants (ninhydrin and Eu(3+)) was fabricated by sol-gel method. The experimental parameters affecting the determination of Phe, such as the concentrations of immobilized reagents, the pH value, the reaction time and temperature were optimized. Under optimum conditions, the fluorescence intensity of Phe-ninhydrin-Eu(3+) system was linearly proportional to the concentration of Phe in the range from 5×10(-5) to 2×10(-3) mol L(-1), and the limit of detection was found to be 5.2×10(-6) mol L(-1). The relative standard deviation was 2.6% for ten replicate measurements of 1.5×10(-4) mol L(-1) of Phe. The method has merits of sensitivity, simplicity and low cost, and has been applied to the determination of Phe in artificial serum.
Collapse
Affiliation(s)
- Kun Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi, People's Republic of China
| | | | | |
Collapse
|