Array lead zirconate titanate/glass piezoelectric microcantilevers for real-time detection of Bacillus anthracis with 10 spores/ml sensitivity and 1/1000 selectivity in bacterial mixtures

Abstract

An array of three identical piezoelectric microcantilever sensors ͑PEMSs͒ consisting of a lead zirconate titanate layer bonded to a glass layer was fabricated and examined for simultaneous, in situ, real-time, all-electrical detection of Bacillus anthracis ͑BA͒ spores in an aqueous suspension using the first longitudinal extension mode of resonance. With anti-BA antibody immobilized on the sensor surfaces all three PEMS exhibited identical BA detection resonance frequency shifts at all tested concentrations, 10-10 7 spores/ ml with a standard deviation of less than 10%. The detection concentration limit of 10 spores/ml was about two orders of magnitude lower than would be permitted by flexural peaks. In blinded-sample testing, the array PEMS detected BA in three samples containing BA: ͑1͒ 3.3ϫ 10 3 spores/ ml, ͑2͒ a mixture of 3.3ϫ 10 3 spores/ ml and 3.3 ϫ 10 5 S. aureus ͑SA͒ and P. aeruginosa ͑PA͒ per ml, and ͑3͒ a mixture of 3.3ϫ 10 3 spores/ ml with 3.3ϫ 10 6 SA+ PA/ ml. There was no response to a sample containing only 3.3ϫ 10 6 SA+ PA/ ml. These results illustrate the sensitivity, specificity, reusability, and reliability of array PEMS for in situ, real-time detection of BA spores.

In situ, amplification-free double-stranded mutation detection at 60 copies/ml with thousand-fold wild type in urine

“…Also demonstrated was detection of KRAS mutation at 10 −19 M – 10 −16 M SW480 DNA fragments in urine. Furthermore, it has been demonstrated that there were no interferences between sensors when multiple sensors were used in multiplexed detection tests 43, 54 Therefore, the highly specific in situ , amplification-free and label-free mutation detection can be conducted in a multiplexed fashion.…”

Desenvolvimento de eletrodo impresso utilizando tinta condutiva e deposição por sputtering

“…[27] A Figura 5 mostra a representação de alguns designs possíveis. [46]; na detecção de células vegetativas e esporos de estirpes de Bacillus [47]; na construção de sensores baseados em células para a detecção e avaliação da citotoxidade de patógenos [48], na detecção de esporos do Bacillus glogibii [49]; na detecção in situ e em tempo real de Bacillus anthacis [50]; na detecção e tratamento do câncer [51][52]; no monitoramento da glicose no sangue por um método não invasivo, sem realizar furos na pele para retirada sangue [53], na detecção de baixos níveis de albumina na urina [54], dentre outras.…”