[16a-P3-1~32] 12.7 Biomedical Engineering and Biochips

[16a-P3-13] Pipette tip-type automatic biosensing system with an antibody immobilized chip for detecting biomarker proteins

〇Eri Takano¹, Nobuaki Shimura², Takeshi Akiba², Toshifumi Takeuchi¹ (1.Kobe Univ., 2.System Instruments Co.,Ltd.)

Keywords:Biosensing system, Immunoassay, Biomarker

We developed a pipette tip-type automatic biosensing system for the detection of biomarker proteins. The pipette tip was designed to be able to incorporate a micro-chip immobilized with molecular recognition elements. First, a gold thin layer was formed on the micro-chip by sputtering. The film thickness was estimated to be ca. 150 nm measured using a UV-Vis spectrophotometer. Since this gold substrate has a maximum absorption wavelength of ca. 500 nm, Alexa 647, which have no fluorescence around this wavelength range, was selected as the fluorescent detection probe. Antibodies were immobilized on the gold sputtered micro-chip via bionanocapsules or protein A. The micro-chip was placed inside the designed pipette tip and fluorescent sandwich assay for the target biomarker proteins was carried out. All of the detection procedures including all the liquid handling and detection of the analyte by the fluorescent labeled secondary antibody were automatically performed with a single pipette tip. The quantitativeness of the target biomarker proteins was evaluated from the relationship between the fluorescence intensity and the concentration. The fluorescence intensity increased with the concentration of the target biomarker proteins was increased. Approximately 1 ng/mL of the target biomarker proteins was detected, revealing that the target biomarker was successfully detected by the developed automated system.