Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
권호 표지

Quantitative Alpha Fetoprotein Detection with a Piezoelectric Microcantilever Mass Sensor

압전 마이크로캔틸레버 질량센서를 이용한 정량적 알파태아단백 검출

  • 이상규 (포항공과대학교 기계공학과) ;
  • 조종윤 (포항공과대학교 기계공학과) ;
  • 이열호 (삼성종합기술연구원) ;
  • 전상민 (포항공과대학교 화학공학과) ;
  • 차형준 (포항공과대학교 화학공학과) ;
  • 문원규 (포항공과대학교 기계공학과)
  • Received : 2011.08.03
  • Accepted : 2011.10.07
  • Published : 2011.10.30
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Abstract

Alpha fetoprotein(AFP), which is serological marker for hepatocellular carcinoma, was quantitatively measured by its normal concentration, 10 ng/ml, with a label-free piezoelectric microcantilever mass sensor. The principle of detection is based on changes in the resonant frequency of the piezoelectric microcantilever before and after target molecules are attached to it, and its resonant frequency is measured electrically using a conductance spectrum. The resonant frequency of the developed sensor is approximately 1.34 MHz and the mass sensitivity is approximately 175 Hz/pg. The sensor has high reliability as mass sensor by reducing the effect of surface stress on resonant frequency due to attached proteins. 'Dip and dry' technique was used to react the sensor with reagents for immobilizing AFP antibody on the sensor and detecting AFP antigen. The measured mass of the detected AFP antigen was 6.02 pg at the concentration of 10 ng/ml, and 10.67 pg at 50 ng/ml when the immunoreaction time was 10 min.

비표지 방식의 압전 마이크로캔틸레버 질량센서를 이용하여 간세포암의 혈청표지물질인 알파태아단백(alpha fetoprotein, AFP)을 정상 농도인 10 ng/ml까지 정량적으로 검출하였다. 압전 마이크로캔틸레버 질량센서는 캔틸레버의 질량변화에 의하여 센서의 공진주파수가 변화되는 원리를 이용하여 센서에 붙은 물질의 질량을 측정하며, 센서의 공진주파수는 컨덕턴스 스펙트럼을 이용하여 전기적으로 측정한다. 제작된 센서는 공진 주파수가 약 1.34 MHz, 질량 민감도가 약 175 Hz/pg이며 단백질이 붙을 때 캔틸레버의 표면 스트레스 변화에 대한 센서의 공진 주파수 변화를 줄일 수 있도록 설계되어 질량센서로써 신뢰도를 높였다. 'Dip and dry' 방법으로 캔틸레버의 프로브 영역을 시약과 반응시켜서 AFP 항체를 고정화하고 AFP 항원을 검출하는 실험을 수행하였다. 10 ng/ml과 50 ng/ml농도의 항원에서 10분간 항원-항체 면역반응을 시켰을 때 센서에 검출된 항원의 질량이 각각 6.02 pg과 10.67 pg이다.

Keywords

References

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