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Midterm Report Professor: Cheng-Hsien, Liu Student: Yi-Jou, Lin Date: 2009/11/03 A HIGH SENSITIVITY CARBON NANOTUBES ENHANCED PZT DIAPHRAM-BASED IMMUNOSENSOR.

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Presentation on theme: "Midterm Report Professor: Cheng-Hsien, Liu Student: Yi-Jou, Lin Date: 2009/11/03 A HIGH SENSITIVITY CARBON NANOTUBES ENHANCED PZT DIAPHRAM-BASED IMMUNOSENSOR."— Presentation transcript:

1 Midterm Report Professor: Cheng-Hsien, Liu Student: Yi-Jou, Lin Date: 2009/11/03 A HIGH SENSITIVITY CARBON NANOTUBES ENHANCED PZT DIAPHRAM-BASED IMMUNOSENSOR ARRAY T. Xu 1, J.M. Miao 1 *, Z.H. Wang 1, Y.S. Liu 2 and C.M. Li 2 1 Micromachines Centre, Nanyang Technological University, Singapore 2 School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 1/12

2 Introduction  Piezoelectric Biosensors - Micro-machined catilever - Quartz-Crystal Microbalance System (QCMS) - Micro-diaphragm 2/12

3 Introduction  Piezoelectric Biosensors  Transduce different phenomena, such as changes of mass, temperature, heat, or stress, into bending or a change in resonant frequency High sensitivity Label-free detection  Low quality merit factor  Fragility of the devices Micro-machined catilever Quartz-Crystal Microbalance System (QCMS) Micro-diaphram Fig 1. Scheme of the cantilever bending due to a biomolecular interaction between an immobilized receptor and its target. Only the specific recognition causes a change on the surface stress driving to the bending of the cantilever. 3/12

4 Introduction  Piezoelectric Biosensor  based on quartz crystal resonators, and measured by a resonance frequency decrease, as a result of the superficial mass increase Good frequency stability and reproducibility  Unable to full fill the requirements as the solid quartz crystal lacks of integration Micro-machined catilever Micro-machined catilever Quartz-Crystal Microbalance System (QCMS) Micro-diaphram Fig.2 Libra DNA-sensor and piezoelectric quartz. Fig. 3. Scheme of DNA immobilization and hybridization on golden quartz. 4/12

5 Introduction  Piezoelectric Biosensors High sensitivity High limit of detection Micro-machined catilever Micro-machined catilever Quartz-Crystal Microbalance System (QCMS) Micro-diaphram A HIGH SENSITIVITY CARBON NANOTUBES ENHANCED PZT DIAPHRAM-BASED IMMUNOSENSOR ARRAY T. Xu 1, J.M. Miao 1 *, Z.H. Wang 1, Y.S. Liu 2 and C.M. Li 2 1 Micromachines Centre, Nanyang Technological University, Singapore 2 School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore generate stronger output signal detect the minimum concentration of the analyte 5/12

6 Introduction  Piezoelectric Biosensors  How to improve the sensitivity? (1) Gold-nanoparticles (2) Carbon nanotubes (CNTs) Micro-machined catilever Micro-machined catilever Quartz-Crystal Microbalance System (QCMS) Micro-diaphram A HIGH SENSITIVITY CARBON NANOTUBES ENHANCED PZT DIAPHRAM-BASEDIMMUNOSENSOR ARRAY T. Xu 1, J.M. Miao 1 *, Z.H. Wang 1, Y.S. Liu 2 and C.M. Li 2 1 Micromachines Centre, Nanyang Technological University, Singapore 2 School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore Provide a 3D platform  The high density and weight of the gold might deposit and cause peizoelectric diaphragm deformation  reliability problems during the immobilization process Extremely high surface area, 400 m 2 /g theoretically Enhance the electrochemical reactivity of some molecules Useful for label-free electrochemical detection  Deposit on the electrodes with applied voltage 6/12

7 Fabrication of piezoelectric diaphragm-based biosensor array SOI wafer PZT= Pb(Zr 0.52 Ti 0.48 )O 3 TiO 2 /Pt Si 3 N 4 Ti/Pt deposit Deposit Patterned &etching Sputtered & patterned DRIE Top electrode bottom electrode 7/12

8 Fabrication of piezoelectric diaphragm-based biosensor array Fig. 4. Images of the fabricated biosensor array. (a) Top view of an optical image of the device. (b)Enlarged optical image of the active PZT diaphragm. (c) SEM image of the reaction chamber on the backside of the diaphragm. Fig 5. Sketched immobilization processes for the CNT enhanced PZT biosensor. -goat IgG Anti-goat IgG 8/12

9 Results  FSEM & AFM images Fig 6. FESEM (a, b) and AFM (c, d) micrographs of CNTs. (a) & (c) CNTs were pretreated by SDS. (b) & (d) CNTs after absorbing goat IgGs. 58-66 nm 82-105 nm 9/12

10 Results Figure 4. Detailed frequency shift of the two-sensor array (a)without CNTs, (b) with CNTs after each immobilization processes Figure 5. Relationship between the frequency depression and concentration of the added anti-goat IgG. High sensitivity High limit of detection 10/12

11 References  L.G. Carrascosa, M. Moreno, M. Alvarez, L. M.Lechuga, “Nanomechanical biosensors: a new sensing tool”, Trend Anal. Chem., vol. 25, pp. 196-206, 2006.  R. Raiteri, M. Grattarola, H. J. Butt, and P. Skladal, “Micromechanical cantilever- based biosensors”, Sens. Actuators B, vol. 79, pp. 115-126, 2001.  N. Perrot, E. Antoine, and C. Compere, “In situ QCM DNA-biosensor probe modification” Sens. Actuators B, vol. 120, pp. 329-337, 2006.  Myriam Passamano, Monica Pighini, “QCM DNA-sensor for GMOs detection”, Sens. Actuators B, vol. 118, pp. 177-181, 2006. 11/12

12 Thank you for your attention!! 12/12


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