RESUMO
A method in which a permanent magnet is introduced onto polydiacetylene (PDA) vesicle chips is introduced for enhancement of the fluorescence of PDA vesicles. This strategy can be applied to general antibody-based PDA vesicle chips to detect clinically important biomarkers for disease diagnosis.
Assuntos
Técnicas Biossensoriais/métodos , Polímeros , Poli-Inos , Neoplasias da Próstata/diagnóstico , Anticorpos Imobilizados , Anticorpos Monoclonais , Técnicas Biossensoriais/estatística & dados numéricos , Biotina , Fluorescência , Humanos , Fenômenos Magnéticos , Masculino , Microscopia Eletrônica de Varredura , Polímero Poliacetilênico , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Estreptavidina , alfa 1-Antiquimotripsina/sangue , alfa-Macroglobulinas/análiseRESUMO
Herein, we demonstrate three strategies of signal amplification for ultrasensitive detection of human immunoglobulin E (hIgE) based on poly(di-acetylene) supramolecules. To fabricate the ultrasensitive PDA biosensor, ethylenediamine as an interlinker and aptamer as a receptor were introduced into the chip fabrication process. Using the prepared PDA liposome biosensor, the hIgE could be detected up to below 1.0 ng/ml by a primary response. In order to accomplish more ultrasensitive detection of protein on a PDA biosensor, polyclonal hIgE antibody was employed as an external mechanical force for the inducement of a secondary response. As a result, a PDA liposome biosensor sensitivity as high as 0.01 ng/ml for the target hIgE was obtained, with a sensitivity which is one hundred times of that of the method without signal amplification. These results indicate that the proposed strategies were capable of ultrasensitive quantitative and qualitative analyses of biomolecules without non-specific binding of non-target proteins.
Assuntos
Aptâmeros de Nucleotídeos/química , Imunoglobulina E/análise , Lipossomos/química , Polímeros/química , Poli-Inos/química , Fluorescência , Humanos , Hipersensibilidade/diagnóstico , Polímero Poliacetilênico , Sensibilidade e EspecificidadeRESUMO
In this study, hybrid stimulus was initially introduced to improve the sensitivity of PDA vesicle chip for detection of prostate-specific antigen-α1-antichymotrypsin (PSA-ACT) complex. The strategy of hybrid stimulus on PDA vesicle chip offers the amplification method of fluorescent signal which combines a primary response by the immune reaction of antigen-antibody and a secondary response by the mechanical pressure of pAb-conjugated magnetic beads. As the primary response result on PDA vesicle chip, the PSA-ACT complex in PBS buffer was detected at 10 ng/mL. However, this detection sensitivity was insufficient for diagnosis of prostate cancer because the normal human PSA concentration is less than 4.0 ng/mL. To solve this problem, polyclonal PSA antibody-conjugated magnetic beads were used as an amplifying agent after primary immunoresponse. As a result, the PSA-ACT complex concentrations (as low as 0.1 ng/mL) could be detected in the PBS buffer sample. Therefore, this result can be applied to various fields, such as the detection of cells, proteins, and DNA for sensitive and specific biosensing based on PDA supramolecules.