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A piezoelectric immunosensor using hybrid self-assembled monolayers for detection of Schistosoma japonicum.

Wang S, Yin T, Zeng S, Che H, Yang F, Chen X, Shen G, Wu Z - PLoS ONE (2012)

Bottom Line: The correlation coefficients reached 0.973.We have developed a new, simple, sensitive, and reusable piezoelectric immunosensor that directly detects SjAb in the serum.This method may represent an alternative to the current diagnostic methods for S. japonicum infection in the clinical laboratory or for analysis outside the laboratory.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Schistosomiasis in Hunan, Department of Parasitology, Xiangya Medical College, Central South University, Changsha, China. spwang@126.com

ABSTRACT

Background: The parasite Schistosoma japonicum causes schistosomiasis disease, which threatens human life and hampers economic and social development in some Asian countries. An important lesson learned from efforts to reduce the occurrence of schistosomiasis is that the diagnostic approach must be altered as further progress is made towards the control and ultimate elimination of the disease.

Methodology/principal findings: Using mixed self-assembled monolayer membrane (mixed SAM) technology, a mixture of mercaptopropionic acid (MPA) and mercaptoethanol (ME) was self-assembled on the surface of quartz crystals by gold-sulphur-bonds. Soluble egg antigens (SEA) of S. japonicum were then cross-linked to the quartz crystal using a special coupling agent. As compared with the traditional single self-assembled monolayer immobilization method, S. japonicum antigen (SjAg) immobilization using mixed self-assembled monolayers exhibits much greater immunoreactivity. Under optimal experimental conditions, the detection range is 1:1500 to 1:60 (infected rabbit serum dilution ratios). We measured several infected rabbit serum samples with varying S. japonicum antibody (SjAb) concentrations using both immunosensor and ELISA techniques and then produced a correlation analysis. The correlation coefficients reached 0.973.

Conclusions/significance: We have developed a new, simple, sensitive, and reusable piezoelectric immunosensor that directly detects SjAb in the serum. This method may represent an alternative to the current diagnostic methods for S. japonicum infection in the clinical laboratory or for analysis outside the laboratory.

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Effect of ME concentration in mixed SAM on SjAg immobilization.The best dose of ME in the mixed membrane was determined to be 70%.
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pone-0030779-g001: Effect of ME concentration in mixed SAM on SjAg immobilization.The best dose of ME in the mixed membrane was determined to be 70%.

Mentions: The mixed SAM has two ends, which are made up of carboxyl compounds with different functional groups. The carboxyl at one end of the MPA carboxyl compound was used to covalently bond various immune biological molecules after activation by the coupling agent. The hydroxyl at one end of the ME sulfhydryl compounds functioned as a diluent in the immobilization of biological materials. The optimization of the amount of diluent in the membrane played a key role in controlling the concentration of biological molecules (antigen or antibody) on the surface of the sensor probe and in improving the performance of the detection method [35], [36]. Figure 1 shows the impact of the ME diluent content in the mixed film on the immobilization of SjAg. The response frequency of the sensor gradually increases with the proportion of ME, and the peak sensor frequency response occurs when the ratio reaches 70% (Figure 1). This indicates that, at this time, the immobilized SjAg molecules on the surface of the sensor are in good order and the steric hindrances are small, which is indicative of an immune response. A decrease in the proportion of ME below 70% may be attributed to a lack of MPA in the mixed membrane leading to the inadequate SjAg immobilization on the surface of the sensor, which results in a decrease in the frequency. Therefore, a 70% dose of ME in the mixed membrane was selected for this experiment.


A piezoelectric immunosensor using hybrid self-assembled monolayers for detection of Schistosoma japonicum.

Wang S, Yin T, Zeng S, Che H, Yang F, Chen X, Shen G, Wu Z - PLoS ONE (2012)

Effect of ME concentration in mixed SAM on SjAg immobilization.The best dose of ME in the mixed membrane was determined to be 70%.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3383785&req=5

pone-0030779-g001: Effect of ME concentration in mixed SAM on SjAg immobilization.The best dose of ME in the mixed membrane was determined to be 70%.
Mentions: The mixed SAM has two ends, which are made up of carboxyl compounds with different functional groups. The carboxyl at one end of the MPA carboxyl compound was used to covalently bond various immune biological molecules after activation by the coupling agent. The hydroxyl at one end of the ME sulfhydryl compounds functioned as a diluent in the immobilization of biological materials. The optimization of the amount of diluent in the membrane played a key role in controlling the concentration of biological molecules (antigen or antibody) on the surface of the sensor probe and in improving the performance of the detection method [35], [36]. Figure 1 shows the impact of the ME diluent content in the mixed film on the immobilization of SjAg. The response frequency of the sensor gradually increases with the proportion of ME, and the peak sensor frequency response occurs when the ratio reaches 70% (Figure 1). This indicates that, at this time, the immobilized SjAg molecules on the surface of the sensor are in good order and the steric hindrances are small, which is indicative of an immune response. A decrease in the proportion of ME below 70% may be attributed to a lack of MPA in the mixed membrane leading to the inadequate SjAg immobilization on the surface of the sensor, which results in a decrease in the frequency. Therefore, a 70% dose of ME in the mixed membrane was selected for this experiment.

Bottom Line: The correlation coefficients reached 0.973.We have developed a new, simple, sensitive, and reusable piezoelectric immunosensor that directly detects SjAb in the serum.This method may represent an alternative to the current diagnostic methods for S. japonicum infection in the clinical laboratory or for analysis outside the laboratory.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Schistosomiasis in Hunan, Department of Parasitology, Xiangya Medical College, Central South University, Changsha, China. spwang@126.com

ABSTRACT

Background: The parasite Schistosoma japonicum causes schistosomiasis disease, which threatens human life and hampers economic and social development in some Asian countries. An important lesson learned from efforts to reduce the occurrence of schistosomiasis is that the diagnostic approach must be altered as further progress is made towards the control and ultimate elimination of the disease.

Methodology/principal findings: Using mixed self-assembled monolayer membrane (mixed SAM) technology, a mixture of mercaptopropionic acid (MPA) and mercaptoethanol (ME) was self-assembled on the surface of quartz crystals by gold-sulphur-bonds. Soluble egg antigens (SEA) of S. japonicum were then cross-linked to the quartz crystal using a special coupling agent. As compared with the traditional single self-assembled monolayer immobilization method, S. japonicum antigen (SjAg) immobilization using mixed self-assembled monolayers exhibits much greater immunoreactivity. Under optimal experimental conditions, the detection range is 1:1500 to 1:60 (infected rabbit serum dilution ratios). We measured several infected rabbit serum samples with varying S. japonicum antibody (SjAb) concentrations using both immunosensor and ELISA techniques and then produced a correlation analysis. The correlation coefficients reached 0.973.

Conclusions/significance: We have developed a new, simple, sensitive, and reusable piezoelectric immunosensor that directly detects SjAb in the serum. This method may represent an alternative to the current diagnostic methods for S. japonicum infection in the clinical laboratory or for analysis outside the laboratory.

Show MeSH
Related in: MedlinePlus