Compact and automated eDNA sampler for in situ monitoring of marine environments.

Using environmental DNA (eDNA) to monitor biodiversity in aquatic environments is becoming an efficient and cost-effective alternative to other methods such as visual and acoustic identification. Until recently, eDNA sampling was accomplished primarily through manual sampling methods; however, with technological advances, automated samplers are being developed to make sampling easier and more accessible. This paper describes a new eDNA sampler capable of self-cleaning and multi-sample capture and preservation, all within a single unit capable of being deployed by a single person.

An Automated Microfluidic Analyzer for Monitoring of Total Alkalinity.

We have designed, built, tested, and deployed an autonomous analyzer for seawater total alkalinity. Such analyzers are required to understand the ocean carbon cycle, including anthropogenic carbon dioxide (CO) uptake and for mitigation efforts via monitoring, reporting, and verification of carbon dioxide removal through ocean alkalinity enhancement. The microfluidic nature of our instrument makes it relatively lightweight, reagent efficient, and amenable for use on platforms that would carry it on long-term deployments.

A submersible phosphate analyzer for marine environments based on inlaid microfluidics.

sensors are needed to further our understanding of phosphate flux dynamics in marine environments during short term events such as tidal cycles, algae blooms and runoff periods. Here, we present a fully automated phosphate analyzer based on an inlaid microfluidic absorbance cell technology. The microfluidic device employs colorimetric absorbance spectrophotometry, using the phosphomolybdenum blue (PMB) assay modified by the addition of polyvinylpyrrolidone (PVP), to measure phosphate concentrations in seawater.

Simultaneous Absorbance and Fluorescence Measurements Using an Inlaid Microfluidic Approach.

A novel microfluidic optical cell is presented that enables simultaneous measurement of both light absorbance and fluorescence on microlitre volumes of fluid. The chip design is based on an inlaid fabrication technique using clear and opaque poly(methyl methacrylate) or PMMA to create a 20.2 mm long optical cell.

An Energy Efficient Thermally Regulated Optical Spectroscopy Cell for Lab-on-Chip Devices: Applied to Nitrate Detection.

Reagent-based colorimetric analyzers often heat the fluid under analysis for improved reaction kinetics, whilst also aiming to minimize energy use per measurement. Here, a novel method of conserving heat energy on such microfluidic systems is presented. Our design reduces heat transfer to the environment by surrounding the heated optical cell on four sides with integral air pockets, thereby realizing an insulated and suspended bridge structure.