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A 1-G?? CMOS transimpedance amplifier (TIA) suitable for processing sub-nA-level currents in electrochemical biosensor signal-acquisition circuits is presented. Use of a two-stage active transconductor provides resistive feedback in place of a large-area linear resistor. The TIA feedback loop is engineered to suppress output offset caused by DC input leakage currents of ??0.9 nA. A mechanism to tune the low-frequency cutoff of the TIA from 0.7 Hz to 500 Hz is implemented which permits operation under variable environmental conditions. Simulated and experimental results from a custom TIA fabricated in a 3.3-V 0.35-??m CMOS process are presented.

Plasmonic materials constitute one of the most explored platforms in the past decade for biological sensing, as they offer a wide range of advantages in respect to the currently available tests employed in either screening or medical diagnosis.The detection of leukaemia cancer markers was chosen as the medical applications in the evaluation of the sensing capabilities of these platforms. Particularly, nanohole arrays on gold films have already been demonstrated to be efficientsensing elements for the study of protein protein interactions. In this work,nanohole arrays platforms were optimized by studying the combinations of shape, diameter, aspect ratio, polarization and periodicity that lead to the highest sensitivity. In addition, different nanohole arrays substrates fabricated by UV-nanolithography and interference lithography were characterized and compared to the structures made by conventional focus ion beam (FIB) milling. Analytes derived from blood sample of leukemia cancer patients were detected on these structures with great sensitivity and specificity, demonstrating a large potential for medical applications. Furthermore, the development and characterization of a cost-effective system capable of detecting leukaemia cancer markers with comparable limit of detection and sensitivity as commercial platforms was started. With future development, this platform could provide advantages in terms of miniaturization, analysis time and the integration as an easy-to-use lab-on-chip device for diagnostics. / Graduate / 0494 / cvalsecc@gmail.com

Plasmonic materials constitute one of the most explored platforms in the past decade for biological sensing, as they offer a wide range of advantages in respect to the currently available tests employed in either screening or medical diagnosis.The detection of leukaemia cancer markers was chosen as the medical applications in the evaluation of the sensing capabilities of these platforms. Particularly, nanohole arrays on gold films have already been demonstrated to be efficientsensing elements for the study of protein – protein interactions. In this work,nanohole arrays platforms were optimized by studying the combinations of shape, diameter, aspect ratio, polarization and periodicity that lead to the highest sensitivity. In addition, different nanohole arrays substrates fabricated by UV-nanolithography and interference lithography were characterized and compared to the structures made by conventional focus ion beam (FIB) milling. Analytes derived from blood sample of leukemia cancer patients were detected on these structures with great sensitivity and specificity, demonstrating a large potential for medical applications. Furthermore, the development and characterization of a cost-effective system capable of detecting leukaemia cancer markers with comparable limit of detection and sensitivity as commercial platforms was started. With future development, this platform could provide advantages in terms of miniaturization, analysis time and the integration as an easy-to-use lab-on-chip device for diagnostics. / Graduate / 0494 / cvalsecc@gmail.com

Ability to diagnose cancer before it progresses into advanced stages is highly desirable for the best treatment outcome. A sensitive test to analyze complex samples for specific cancer biomarkers would provide with important prognostic information and help to select the best treatment regimen. A highly robust, ultra sensitive and cost-effective electronic chip platform was used to detect nucleic acid biomarkers in heterogeneous biological samples without any amplification or purification. Chronic myelogenous leukemia (CML) was chosen as a model disease due to its hallmark genetic abnormality. This disease state therefore has an ideal market to test the detection of the fusion transcripts in complex samples, such as blood. It was shown that the CML-related fusion can be detected from unpurified cell lysates and as low as 10 cells were needed for detection. Finally, patient samples were analyzed using the assay and the fusion transcripts were accurately identified in all of them.

Ability to diagnose cancer before it progresses into advanced stages is highly desirable for the best treatment outcome. A sensitive test to analyze complex samples for specific cancer biomarkers would provide with important prognostic information and help to select the best treatment regimen. A highly robust, ultra sensitive and cost-effective electronic chip platform was used to detect nucleic acid biomarkers in heterogeneous biological samples without any amplification or purification. Chronic myelogenous leukemia (CML) was chosen as a model disease due to its hallmark genetic abnormality. This disease state therefore has an ideal market to test the detection of the fusion transcripts in complex samples, such as blood. It was shown that the CML-related fusion can be detected from unpurified cell lysates and as low as 10 cells were needed for detection. Finally, patient samples were analyzed using the assay and the fusion transcripts were accurately identified in all of them.

München, Techn. Universiẗat, Diss., 2004.

University, Diss., 2001--Bonn.

Bielefeld, Univ., Diss., 2004

Universiẗat, Diss., 2001--Tübingen.