Multifunction fluorescence open source in vivo/in vitro imaging system (openIVIS).

The widespread availability and diversity of open-source microcontrollers paired with off-the-shelf electronics and 3D printed technology has led to the creation of a wide range of low-cost scientific instruments, including microscopes, spectrometers, sensors, data loggers, and other tools that can be used for research, education, and experimentation. These devices can be used to explore a wide range of scientific topics, from biology and chemistry to physics and engineering. In this study, we designed and built a multifunction fluorescent open source in vivo/in vitro imaging system (openIVIS) system that integrates a Raspberry Pi with commercial cameras and LEDs with 3D printed structures combined with an acrylic housing. Our openIVIS provides three excitation wavelengths of 460 nm, 520 nm, and 630 nm integrated with Python control software to enable fluorescent measurements across the full visible light spectrum. To demonstrate the potential applications of our system, we tested its performance against a diverse set of experiments including laboratory assays (measuring fluorescent dyes, using optical nanosensors, and DNA gel electrophoresis) to potentially fieldable applications (plant and mineral imaging). We also tested the potential use for a high school biology environment by imaging small animals and tracking their development over the course of ten days. Our system demonstrated its ability to measure a wide dynamic range fluorescent response from millimolar to picomolar concentrations in the same sample while measuring responses across visible wavelengths. These results demonstrate the power and flexibility of open-source hardware and software and how it can be integrated with customizable manufacturing to create low-cost scientific instruments with a wide range of applications. Our study provides a promising model for the development of low-cost instruments that can be used in both research and education.

Nanoparticle-Based Liquid-Liquid Extraction for the Determination of Metal Ions.

Traditional liquid phase extraction techniques that use optically responsive ligands provide benefits that enable cost-efficient and rapid measurements. However, these approaches have limitations in their excessive use of organic solvents and multistep procedures. Here, we developed a simple, nanoscale extraction approach by replacing the macroscopic organic phase with hydrophobic polymeric nanoparticles that are dispersed in an aqueous feed. The concentration of analytes in polymeric nanoparticle suspensions is governed by similar partition principles to liquid-liquid phase extraction techniques. By encasing optically responsive metal ligands inside polymeric nanoparticles, we introduce a one-step metal quantification assay based on traditional two-phase extraction methodologies. As an initial proof of concept, we encapsulated bathophenanthroline (BP) inside the particles to extract then quantify Fe2+ with colorimetry in a dissolved supplement tablet and creek water. These Fe2+ nanosensors are sensitive and selective and report out with fluorescence by adding a fluorophore (DiO) into the particle core. To show that this new rapid extraction assay is not exclusive to measuring Fe2+, we replaced BP with either 8-hydroxyquinoline or bathocuproine to measure Al3+ or Cu+, respectively, in water samples. Utilizing this nanoscale extraction approach will allow users to rapidly quantify metals of interest without the drawbacks of larger-scale phase extraction approaches while also allowing for the expansion of phase extraction methodologies into areas of biological research.