A portable chemical toxicity biochip based on electronic enzymatic monitoring of cytotoxic effects on fish cells

Abstract

Herein we describe a miniaturised chemical toxicity analyser with capacity to assess water quality without intervention of laboratory equipment. The device, as presented, integrates living cells and electrode-based sensors to monitor cell viability upon exposure to toxic chemicals. The methodology involved cultured fish cells Poeciliopsis lucidia hepatocellular carcinoma (PLHC-1) and Oncorhynchus mykiss rainbow trout gonad (RTG-2) cells, exposed to toxic chemicals (CdCl 2 and pentachlorophenol (PCP)) after which the activity of a cellular enzyme, acid phosphatase (AP) was measured. Reduced AP activity was quantified electrochemically, allowing IC 50 values (50% reduction in AP activity) to be determined. Fish cells are a relevant model of the toxicity risks posed by contaminated water to aquatic health. Such cells are relatively slow growing and do not require a source of CO 2 for incubation, thus ensuring portability for single-use point of site applications. The 24 hour IC 50 values determined for CdCl 2 in the fish cell lines (16.2 ± 0.7 and 91 ± 11 M for PLHC and RTG-2, respectively) were in agreement with those found using the MTT assay (16.3 ± 1.6 and 164 ± 96 M). In the case of PCP, the IC 50 value in PHLC cells (127 ± 22 M) suggested enhanced sensitivity towards PCP compared with the MTT assay (IC 50 > 160 M). The optimised electronic assay was transferred to a prototype integrated assay cartridge with associated fluidic and transducer elements. This device (TOXOR) monitored changes in the metabolic state of fish cells, realising high-value toxicity information as a potential early warning on-site screening system.

Electrochemical Biosensors for Detection of Pesticides and Heavy Metal Toxicants in Water: Recent Trends and Progress

“…Previously, our group investigated the use of Poeciliopsis lucidia hepatocellular carcinoma (PLHC-1) topminnow and Oncorhynchus mykiss rainbow trout gonad (RTG-2) cells as part of an electrochemical cytotoxicity assay and portable chemical toxicity biochip. 156 Electrochemical measurements of changes in cellular acid phosphatase activity were used to evaluate cell viability following exposure to micromolar concentrations of Cd 2+ ions. The fish cells were sensitive Cd 2+ ions and had advantages over eukaryotic cells in that they grew slowly and could be cultured at 20 °C without the need for a supply of CO 2 .…”

“…Its performance was compared with that of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) optical cytotoxicity assay. Previously, our group investigated the use of Poeciliopsis lucidia hepatocellular carcinoma (PLHC-1) topminnow and Oncorhynchus mykiss rainbow trout gonad (RTG-2) cells as part of an electrochemical cytotoxicity assay and portable chemical toxicity biochip . Electrochemical measurements of changes in cellular acid phosphatase activity were used to evaluate cell viability following exposure to micromolar concentrations of Cd 2+ ions.…”

Smartphone-Assisted Three Dimensional-Printed Acute Toxicity Detection: Mitigating the Impact of Sample Color

“…3 Thus, acute aquatic toxicity testing is more than just a scientific procedure; it is a guiding force in our pursuit to protect and preserve aquatic ecosystems against the escalating chemical challenges of contemporary society. 4 Commonly used organisms for toxicity detection include algae, 5 fish, 6 and daphnia. 7 Their limitations generally include long time-consuming and significant individual differences.…”

“…Commonly used organisms for toxicity detection include algae, fish, and daphnia . Their limitations generally include long time-consuming and significant individual differences. − In contrast, bioluminescent bacteria that can respond quickly have become essential for ecotoxicology research .…”