Whole cell based electrical impedance sensing approach for a rapid nanotoxicity assay

Abstract

A whole cell based biosensor for rapid real-time testing of human and environmental toxicity of nanoscale materials is reported. Recent studies measuring nanoparticle cytotoxicity in vitro provide a final measurement of toxicity to a cell culture overlooking the ongoing cytotoxic effects of the nanoparticles over the desired timeframe. An array biosensor capable of performing multiple cytotoxicity assays simultaneously was designed to address the need for a consistent method to measure real-time assessments of toxicity. The impedimetric response of human lung fibroblasts (CCL-153) and rainbow trout gill epithelial cells (RTgill-W1) when exposed to gold and silver nanoparticles (AuNPs, AgNPs), single walled carbon nanotubes (SWCNTs) and cadmium oxide (CdO) was tested. Exposure to CdO particles exhibited the fastest rate of cytotoxicity and demonstrated the biosensor's ability to monitor toxicity instantaneously in real time. Advantages of the present method include shorter run times, easier usage, and multi-sample analysis leading to a method that can monitor the kinetic effects of nanoparticle toxicity continuously over a desired timeframe.

High throughput toxicity screening and intracellular detection of nanomaterials

“…Assays for cellular metabolic activity, oxidative stress evaluation, apoptosis detection, and cell membrane integrity49, 50, 51, 52, 53, 54, 55 have been developed for analyzing cytotoxicity of chemicals and these are widely used also in NM‐induced cytotoxicity screening. The methods are time‐consuming, labor‐intensive, complex, and in some instances unreliable owing to NM interferences 53, 56, 57.…”

“…The methods are time‐consuming, labor‐intensive, complex, and in some instances unreliable owing to NM interferences 53, 56, 57. The reagents employed in such methods may interact with some of the tested NMs or may interfere with spectrophotometric readings, leading to unreliable results 49, 50, 55. Conventional assays focus on specific endpoints, without providing information about the dynamic biological processes leading to those endpoints, or the specific time points and concentrations at which different toxic effects are induced by NMs 54, 58.…”

β-Amyloid Biomarker Detection for Alzheimer’s Disease

“…This system studies the system response to the application of periodic small amplitude AC signals [17]. As mentioned earlier, monitoring the morphology of the Ab is important.…”

“…A research group developed a nanostructured biosensor using AuNPs, which main goal was also to measure Ab 42 using EIS as their main analysis tool. Using EIS they measured the impedance between the electrode and the solution at a specific frequency [17]. The impedance changes when the target analyte is immobilized on the probe.…”

Development of Point-of-Care Testing Sensors for Biomarker Detection

“…The EIS chip design was previously reported. 125 In short, as cells are placed in each well of the chip, they settle down onto the electrode surface creating a barrier for the flowing current increasing the resistance measurements. Thus, it is possible to monitor the cell attachment and proliferation from the change in resistance measurements.…”