Quantitative detection of carbon nanotubes in biological samples by an original method based on microwave permittivity measurements

摘要

Due to their nanoscale, morphology, and chemical composition, the tracking and theudquantitative analysis of carbon nanotubes (CNTs) in biological samples still represent hugeudchallenges. A new technique for the quantitative and accurate detection of CNTs in variousudbiological samples at different scales (whole organisms to organs) was developed usingudamphibian larvae exposed to double-walled CNTs (DWCNTs). This technique is based onudthe dielectric relaxation of ultra-low volume suspensions under a microwave electromagneticudfield. CNT concentrations were consequently extracted from complex permittivityudmeasurements at 5 GHz, making possible to quantitatively assess the animal exposure toudCNTs. Our results indicate a detection threshold of 0.02 lg of DWCNTs, which is the lowestudachieved in the literature to date