In this paper we demonstrate a potentiostat built with a single commercially available integrated circuit (IC) that does not require any external electronic components to perform electrochemical experiments. This is done using the capabilities of the Programmable System on a Chip (PSoC®) by Cypress Semiconductor, which integrates all of the necessary electrical components. This is in contrast to other recent papers that have developed potentiostats but require technical skills or specialized equipment to produce. This eliminates the process of having to make a printed circuit board and soldering on electronic components. To control the device, a graphical user interface (GUI) was developed in the python programming language. Python is open source, with a style that makes it easy to read and write programs, making it an ideal choice for open source projects. As the developed device is open source and based on a PSoC, modification to implement other electrochemical techniques is straightforward and only requires modest programming skills, but no expensive equipment or difficult techniques. The potentiostat developed here adds to the growing amount of open source laboratory equipment. To demonstrate the PSoC potentiostat in a wide range of applications, we performed cyclic voltammetry (to measure vitamin C concentration in orange juice), amperometry (to measure glucose with a glucose strip), and stripping voltammetry experiments (to measure lead in water). The device was able to perform all experiments and could accurately measure Vitamin C, glucose, and lead.

The objective of this research is to prepare the shell of a curcumin-(CU-) loaded microcapsule by gamma radiationinduced crosslinking between chitosan (CS) and polyethylene glycol diacrylate (PEGDA) for CU delivery. The CS-PEGDA beads were irradiated by a gamma ray at 25 kGy. With confirmation by Fourier transform infrared spectroscopy, the CS-PEGDA microcapsules were successfully synthesized. The yield of irradiation-induced synthesis of CS-PEGDA was 43.94%. The particle size of the beads observed under electron microscopy varied between 60 and 150 µm (x¯90 ± 18.50 µm), with 25.70% of the pores on the surface and a swelling degree of 110.48%. CU was encapsulated within the CS-PEGDA beads affording a yield of 92.6%. The CS-PEGDA beads were more durable to the razor cutting force than the CS beads and maintained their spherical morphology. A CU release study from the loaded CS-PEGDA beads under simulated gastrointestinal conditions revealed gradual, sustained release with a constant rate of 10%-20% over 6 hours. Our results suggest that the CS-PEGDA crosslinking process enabled by gamma irradiation could potentially be applied to the encapsulation of CU for effective drug delivery by oral administration.

Designing with a Programmable System on a Chip (PSoC) allows for entire circuit designs to be implemented with a single commercially available chip and eliminates the need to physically assemble electronic components. This is possible as the PSoC incorporates a microcontroller with digital and analog components into a single package. While this design allows for much easier implementation of circuits, there are some drawbacks. In this paper we will demonstrate one of those drawbacks, high routing resistance in parts of the analog mesh that connects the analog parts and external pins. We show how this resistance can cause measurement errors when the PSoC is implemented as a single chip potentiostat. As the internal analog routing resistance is in the kΩ range, measuring currents in the Kॅ range can cause mV errors, leading to lose of voltage control during electrochemical experiments. We also demonstrate a calibration routine to compensate for this voltage error that reduced the error by over 90%.