Jun-Chau Chien (Advisor)

We have previously demonstrated electrochemical circuits for measuring the concentration of various biomolecules and drugs using structure-switching aptamers. Structure-switching aptamers are single-stranded nucleic acids that can be sequenced to exhibit conformational changes when bound to specific biomolecules. By conjugating aptamers with a redox reporter, voltammetry or amperometry-based measurements can be applied and signals in the nano to pico-amp scale can be captured using transimpedance amplifiers (TIA). Because the signals of interest are very small, noise-cancellation...

Nanostructured materials have become an exciting area of research for the improvement of traditional electronic sensors. The high surface area to volume ratio of nanoflowers, nano-urchins, and nanoporous materials has allowed them to exhibit significant improvements in limit of detection and sensitivity compared to analogous planar sensors. These complex structures have also demonstrated the capability of improving biofouling resistance in complex media by helping to screen fouling agents from the active surface. Despite these advantages, moving this material beyond the laboratory has...

The Electrochemical Aptamer-based (E-AB) sensors provide continuous and real-time monitoring of specific target molecules, including proteins, antibiotics, neurotransmitters, and more. Due to the cost-effectiveness compared to enzyme sensing assays, E-AB platforms hold significant promise for point-of-care devices and precision medicine. However, sensitivity remains a challenge, particularly in the complicated environment, such as blood and serum. While research has achieved a noise level in the picoampere range, enhancing sensitivity is crucial for detecting trace amounts of certain...

Current quantum processor units (QPUs) have achieved over 1,000 qubits (e.g., IBM's Condor processor). However, scaling quantum platforms toward 1 million qubits demands breakthroughs in quantum hardware, connectivity, error correction, and system architecture. To address the scalability of quantum interconnects, Cryo-CMOS control and readout circuits have demonstrated efficacy in reducing wiring complexity, latency, and thermal loads. However, the CMOS circuits limit the active heat load to 1–2 mW/qubit, imposing a limit of approximately 1,000 qubits in state-of-the-art dilution...