Integrated circuit & system design for concurrent amperometric and potentiometric wireless electrochemical sensing

Complementary Metal-Oxide-Semiconductor (CMOS) biosensor platforms have steadily grown in healthcare and commerial applications. This technology has shown potential in the field of commercial wearable technology, where CMOS sensors aid the development of miniaturised sensors for an improved cost of production and response time. The possibility of utilising wireless power and data transmission techniques for CMOS also allows for the monolithic integration of the communication, power and sensing onto a single chip, which greatly simplifies the post-processing and improves the efficiency of data collection. The ability to concurrently utilise potentiometry and amperometry as an electrochemical technique is explored in this thesis. Potentiometry and amperometry are two of the most common transduction mechanisms for electrochemistry, with their own advantages and disadvantages. Concurrently applying both techniques will allow for real-time calibration of background pH and for improved accuracy of readings. To date, developing circuits for concurrently sensing potentiometry and amperometry has not been explored in the literature. This thesis investigates the possibility of utilising CMOS sensors for wireless potentiometric and amperometric electrochemical sensing. To start with, a review of potentiometry and amperometry is evaluated to understand the key factors behind their operation. A new configuration is proposed whereby the reference electrode for both electrochemistry techniques are shared. This configuration is then compared to both the original configurations to determine any differences in the sensing accuracy through a novel experiment that utilises hydrogen peroxide as a measurement analyte. The feasibility of the configuration with the shared reference electrode is proven and utilised as the basis of the electrochemical configuration for the front end circuits. A unique front-end circuit named DAPPER is developed for the shared reference electrode topology. A review of existing architectures for potentiometry and amperometry is evaluated, with a specific focus on low power consumption for wireless applications. In addition, both the electrochemical sensing outputs are mixed into a single output data channel for use with a near-field communication (NFC). This mixing technique is also further analysed in this thesis to understand the errors arising due to various factors. The system is fabricated on TSMC 180nm technology and consumes 28µW. It measures a linear input current range from 250pA - 0.1µW, and an input voltage range of 0.4V - 1V. This circuit is tested and verified for both electrical and electrochemical tests to showcase its feasibility for concurrent measurements. This thesis then provides the integration of wireless blocks into the system for wireless powering and data transmission. This is done through the design of a circuit named SPACEMAN that consists of the concurrent sensing front-end, wireless power blocks, data transmission, as well as a state machine that allows for the circuit to switch between modes: potentiometry only, amperometry only, concurrent sensing and none. The states are switched through re-booting the circuit. The core size of the electronics is 0.41mm² without the coil. The circuit’s wireless powering and data transmission is tested and verified through the use of an external transmitter and a connected printed circuit board (PCB) coil. Finally, the future direction for ongoing work to proceed towards a fully monolithic electrochemical technique is discussed through the next development of a fully integrated coil-on-CMOS system, on-chip electrodes with the electroplating and microfludics, the development of an external transmitter for powering the device and a test platform. The contributions of this thesis aim to formulate a use for wireless electrochemical sensors capable of concurrent measurements for use in wearable devices.Open Acces

Oxobedfordia acid reduces colon cancer cell viability through apoptosis induction and inhibits colon cancer growth in mice model

Purpose: Colon cancer is amongst the most commonly diagnosed carcinoma globally and ranks 3rd highest of all the kinds of tumors. In the present study effect of oxobedfordia acid on colon cancer cell viability and colorectal tumor growth in vivo was investigated.Methods: Cytotoxicity of oxobedfordia acid in SW480, HCT116, and FHC cells was evaluated by MTT assay. Colon cancer in the mice was induced by implanting subcutaneously 2 x 106 HT-29 cells/mouse in the right flank. Various parameters, including cell viability, tumor growth and expression levels of cancer factors, were also assessed.Results: Treatment with oxobedfordia acid significantly reduced viability in SW480 and HCT116 cells (p < 0.05). Furthermore, oxobedfordia acid caused increased miR-331-3p levels in cells. Moreover, oxobedfordia acid caused a significant reduction in NRP2 expression and increased apoptosis induction in SW480 and HCT116 cells. Oxobedfordia acid treatment for 48 h significantly increased p53 and p-c- Jun levels, but reduced Bcl-2 expression in cells (p < 0.05). In the mouse model of colon cancer, oxobedfordia acid significantly retarded tumor growth. Furthermore, in oxobedfordia acid-treated mice, expression of miR-331-3p was elevated while NRP2 level was lowered when compared with control group (p < 0.05).Conclusion: Oxobedfordia acid treatment suppresses colon cancer cell viability and inhibits tumor growth in mice through enhancement of miR-331-3p and reduction in NRP2 expression. Hence, oxobedfordia acid can potentially be developed as an agent for the management of colorectal cancer.&nbsp

Experimental Implementation of Noncyclic and Nonadiabatic Geometric Quantum Gates in a Superconducting Circuit

Quantum gates based on geometric phases possess intrinsic noise-resilience features and therefore attract much attention. However, the implementations of previous geometric quantum computation typically require a long pulse time of gates. As a result, their experimental control inevitably suffers from the cumulative disturbances of systematic errors due to excessive time consumption. Here, we experimentally implement a set of noncyclic and nonadiabatic geometric quantum gates in a superconducting circuit, which greatly shortens the gate time. And also, we experimentally verify that our universal single-qubit geometric gates are more robust to both the Rabi frequency error and qubit frequency shift-induced error, compared to the conventional dynamical gates, by using the randomized benchmarking method. Moreover, this scheme can be utilized to construct two-qubit geometric operations, while the generation of the maximally entangled Bell states is demonstrated. Therefore, our results provide a promising routine to achieve fast, high-fidelity, and error-resilient quantum gates in superconducting quantum circuits

The Internet-of-Things Meets Business Process Management: Mutual Benefits and Challenges

The Internet of Things (IoT) refers to a network of connected devices collecting and exchanging data over the Internet. These things can be artificial or natural, and interact as autonomous agents forming a complex system. In turn, Business Process Management (BPM) was established to analyze, discover, design, implement, execute, monitor and evolve collaborative business processes within and across organizations. While the IoT and BPM have been regarded as separate topics in research and practice, we strongly believe that the management of IoT applications will strongly benefit from BPM concepts, methods and technologies on the one hand; on the other one, the IoT poses challenges that will require enhancements and extensions of the current state-of-the-art in the BPM field. In this paper, we question to what extent these two paradigms can be combined and we discuss the emerging challenges

Insight into the efficient oxidation of methyl-ethyl-ketone over hierarchically micro-mesostructured Pt/K-(Al)SiO 2 nanorod catalysts: Structure-activity relationships and mechanism

Hierarchically micro-mesostructured Pt/K-Al-SiO2 catalysts with regular nanorod (Pt/KA-NRS) and spherical nanoflower-like (Pt/KA-SNFS) morphologies were prepared. The existence of Al atoms generates Brønsted acid sites and reduces silanol groups over the supports, promoting the dispersion of Pt nanoparticles and stability of catalysts. Potassium atoms balance the negative charge of supports and enhance O2 mobility. The Pt/KA-NRS catalysts exhibit unexceptionable low temperature activity, CO2 selectivity, and stability for MEK oxidation. Amongst, 0.27 wt.% Pt/KA-NRS completely converts MEK at just 170 °C (activation energy as low as 37.22 kJ·mol−1), more than 100 °C lower than other typical Pt/Pd supported catalysts reported in the literature. Diacetyl and 2,3-butandiol are the main intermediates during MEK activation, which convert into H2O and CO2 through aldehydes and acids. The excellent catalytic activity of Pt/KA-NRS is ascribed to their regular morphology, high Pt0 content and dispersion, excellent MEK adsorption capacity and superior O2/CO2 desorption capability under low temperature

Establishment and application of health risk ranking model for heavy metals in aquatic products

Objective To develop a scientific and rapid risk ranking model that is suitable for the analysis of data from food chemicals surveillance system. Methods Based on the principles of food safety risk assessment, a series of index were developed for the contamination and toxicity characteristics of chemicals in food, food consumption characteristics of population, and standards violation rate, respectively. Then the logical operation relationship and the standards for assigning scores were set. The model was verified using real surveillance data. Results Total risk scores were calculated using the equation: total risk score = toxicity adjusted content score × violation rate score × consumption score. This model was applied to the risk classification of arsenic, cadmium, mercury and lead in aquatic products in China. The ranking result were in line with those estimated by the classical risk assessment model. Conclusion The model could rank the health risk of heavy metals in aquatic products properly, and can provide a scientific foundation for regulatory priority