Development of a new biosensor array and lab-on-a-chip for portable applications using a label-free detection method

Kallempudi, Sreenivasa Saravan (2011) Development of a new biosensor array and lab-on-a-chip for portable applications using a label-free detection method. [Thesis]

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The detection and quantification of cardiac biomarkers in serum is crucial to diagnose patients in the early stage of a disease. The recent advances in microfluidics technology can improve diagnostics by reducing the application time and integrating several clinical analysis into a single, portable device called lab-on-a-chip (LOC). The development of such immunosensing LOC is a major thrust of the rapidly growing bionanotechnology industry. It involves a multidisciplinary research effort encompassing microfluidics, microelectronics and biochemistry. This thesis work focused on the development of immunoassays on microfabricated gold inter-digitated transducers (IDT) on silica and glass substrates. The concept of label-free, affinity-based biosensing is introduced with a special emphasis to impedance spectroscopy. Different protocols involving the covalent immobilization of cancer risk marker (human epidermal growth factor, hEGFR) and cardiac risk marker proteins C reactive protein (CRP), interleukin (IL6) and nicotinamide phosphoribosyltransferase (Nampt) single stranded deoxyribonucleic acid were investigated. For this, IDTs were fabricated using integrated circuit (IC) fabrication processes providing compatibility for the integration of electronic circuits, for single-chip and lab-on-a-chip biosensing applications. The thesis also involves development of a poly dimethylsiloxane (PDMS)-based fluidic system comprising on-chip actuated mechanism for multi-target immunosensing applications. The fluidic flow is controlled by an applied hydraulic pressure on the micropump. Label-free affinity type sensing was carried out using two different biological recognition elements (a) immunosensing approach using antibodies for hEGFR and IL-6 was employed and the function of the LOC was analyzed for detection of hEGFR and IL-6 as model analytes. A detection limit of 0.1ng/ml of hEGFR and IL-6 in serum was obtained without any signal amplification. (b) label-free affinity-based methodology using ssDNA aptamers specific for Nampt to develop an aptasensor and obtained a detection limit of 1 ng/ml in serum for Nampt, which is the most sensitive detection range with the application of the aptamer for Nampt.
Item Type: Thesis
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK7800-8360 Electronics
Divisions: Faculty of Engineering and Natural Sciences > Academic programs > Electronics
Faculty of Engineering and Natural Sciences
Depositing User: Dila Günay
Date Deposited: 02 Aug 2022 15:53
Last Modified: 02 Aug 2022 15:53

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