title: Immobilized rolling circle amplification on extended-gate field-effect transistors with integrated readout circuits for early detection of platelet-derived growth factor.
abstract: Detection of tumor-related proteins with high specificity and sensitivity is important for early diagnosis and prognosis of cancers. While protein sensors based on antibodies are not easy to keep for a long time, aptamers (single-stranded DNA) are found to be a good alternative for recognizing tumor-related protein specifically. This study investigates the feasibility of employing aptamers to recognize the platelet-derived growth factor (PDGF) specifically and subsequently triggering rolling circle amplification (RCA) of DNAs on extended-gate field-effect transistors (EGFETs) to enhance the sensitivity. The EGFETs are fabricated by the standard CMOS technology and integrated with readout circuits monolithically. The monolithic integration not only avoids the wiring complexity for a large sensor array but also enhances the sensor reliability and facilitates massive production for commercialization. With the RCA primers immobilized on the sensory surface, the protein signal is amplified as the elongation of DNA, allowing the EGFET to achieve a sensitivity of 8.8 pM, more than three orders better than that achieved by conventional EGFETs. Moreover, the responses of EGFETs are able to indicate quantitatively the reaction rates of RCA, facilitating the estimation on the protein concentration. Our experimental results demonstrate that immobilized RCA on EGFETs is a useful, label-free method for early diagnosis of diseases related to low-concentrated tumor makers (e.g., PDGF) for serum sample, as well as for monitoring the synthesis of various DNA nanostructures in real time. Graphical Abstract The tumor-related protein, PDGF, is detected by immobilizing rolling circle amplification on an EGFET with integrated readout circuit.
authors.affiliation: Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 300, Taiwan, Republic of China.
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Lin
authors.affiliation: Institute of Electronics Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan, Republic of China.
authors.forename: Wen-Yang
authors.initials: WY
authors.lastname: Hsu
authors.affiliation: Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, 300, Taiwan, Republic of China.
authors.forename: Yuh-Shyong
authors.initials: YS
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, Chang Gung Memorial Hospital, Chia-Yi, 61363, Taiwan, Republic of China.
authors.forename: Jo-Wen
authors.initials: JW
authors.lastname: Huang
authors.affiliation: Institute of Electronics Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan, Republic of China.
authors.forename: Yueh-Lin
authors.initials: YL
authors.lastname: Chung
authors.affiliation: Institute of Electronics Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan, Republic of China. hchen@ee.nthu.edu.tw.
authors.forename: Hsin
authors.initials: H
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D006801:Humans; D010982:Platelet-Derived Growth Factor / Q000032:analysis*; D015203:Reproducibility of Results; D014173:Transistors, Electronic
chemical_list: D010982:Platelet-Derived Growth Factor
keywords: Amplification; Extended-gate field-effect transistors; Label-free detection; Monolithically integrated circuits; Real-time monitoring; Rolling circle