Monolithic integrated light-emitting-diode/photodetector sensor for photoactive analyte monitoring: design and simulation.

We present the simulation and design optimization of an integrated light-emitting-diode/photodetector (LED-PD) sensor system for monitoring of light absorbance changes developing in analyte-sensitive compounds. The sensor integrates monolithically both components in a single chip, offering advantages such as downsizing, reduced assembly complexity, and lower power consumption. The changes in the optical parameters of the analyte-sensitive ink are detected by monitoring the power transmission from the LED to the PD.

A dataset of color QR codes generated using back-compatible and random colorization algorithms exposed to different illumination-capture channel conditions.

Color QR Codes are often generated to encode digital information, but one also could use colors or to allocate colors in a QR Code to act as a color calibration chart. In this dataset, we present several thousand QR Codes images generated with two different colorization algorithms (random and back-compatible) and several tuning variables in these color encoding. The QR Codes were also exposed to three different channel conditions (empty, augmentation and real-life).

Visible Light-Driven -Type Semiconductor Gas Sensors Based on CaFeO Nanoparticles.

In this work, we present conductometric gas sensors based on -type calcium iron oxide (CaFeO) nanoparticles. CaFeO is a metal oxide (MOx) with a bandgap around 1.9 eV making it a suitable candidate for visible light-activated gas sensors.

A Parts Per Billion (ppb) Sensor for NO with Microwatt (μW) Power Requirements Based on Micro Light Plates.

A film of gas sensitive ZnO nanoparticles has been coupled with a low-power micro light plate (μLP) to achieve a NO-parts-per-billion conductometric gas sensor operating at room temperature. In this μLP configuration, an InGaN-based LED (emitting at 455 nm) is integrated at a few hundred nanometers distance from the sensor material, leading to sensor photoactivation with well controlled, uniform, and high irradiance conditions, and very low electrical power needs. The response curves to different NO concentrations as a function of the irradiance displayed a bell-like shape.

Highly Specific and Wide Range NO Sensor with Color Readout.

We present a simple and inexpensive method to implement a Griess-Saltzman-type reaction that combines the advantages of the liquid phase method (high specificity and fast response time) with the benefits of a solid implementation (easy to handle). We demonstrate that the measurements can be carried out using conventional RGB sensors; circumventing all the limitations around the measurement of the samples with spectrometers. We also present a method to optimize the measurement protocol and target a specific range of NO concentrations.