The use of functionalized AFM tips as molecular sensors in the detection of pesticides

Abstract

Atomic force spectroscopy, a technique derived from Atomic Force Microscopy (AFM), allowed us to distinguish nonspecific and specific interactions between the acetolactate synthase enzyme (ALS) and anti-atrazine antibody biomolecules and the herbicides imazaquin, metsulfuron-methyl and atrazine. The presence of specific interactions increased the adhesion force (F adh ) between the AFM tip and the herbicides, which made the modified tip a powerful biosensor. Increases of approximately 132% and 145% in the F adh values were observed when a tip functionalized with ALS was used to detect imazaquin and metsulfuron-methyl, respectively. The presence of specific interactions between the atrazine and the anti-atrazine antibody also caused an increase in the F adh values (approximately 175%) compared to those observed when using an unfunctionalized tip. The molecular modeling results obtained with the ALS enzyme suggest that the orientation of the biomolecule on the tip surface could be suitable for allowing interaction with the herbicides imazaquin and metsulfuron-methyl.

Nanomechanical Cantilever-Based Sensor: An Efficient Tool to Measure the Binding Between the Herbicide Mesotrione and 4-Hydroxyphenylpyruvate Dioxygenase

“…4 The atomic force microscopy (AFM) cantilever presents a smart platform for the development of highly sensitive and selective sensors that can detect assorted physical, chemical, and biological events. [5][6][7] Its means of detection are based on two AFM techniques: (1) spectroscopy of AFM tips through force curve measurements, 8 and (2) measurement of cantilever de°ection, which analyzes surface stress due to the chemical bindings or reactions occurring on immobilized surfaces. 5,9 Other approaches to de°ection analysis can be accomplished by changing the resonance frequency of the cantilever to the dynamic mode.…”

Aplicações de química teórica no estudo de materiais: métodos in silico para nanomateriais

“…51 Em contraste com o MCV, esses métodos focam sua atenção nas propriedades das malhas de coordenadas e utilizam vantagens matemáticas ao considerar que as funções de onda possam ser obtidas a partir de combinações lineares de ondas planas ou misturas de ondas planas e funções gaussianas. 52 No MCV, a função de onda é definida e o 48 Clark et al (2011), Zimmerman et al (2009), Marchi et al (2009), Tanaka (2013), Barborini e Guidoni (2012), Morales et al (2012), Trail e Maezono (2010). 49 Lester e Hammond (1990), Foulkes et al (2001).…”

“…17 É nesse contexto que as técnicas de MMC tiveram seu desenvolvimento estimulado. 18 13 Da Silva et al (2013Silva et al ( , 2014, Deda et al (2013), Castro Bueno et al (2014). 14 Butt et al (1990).…”

Desenvolvimento de nanodispositivos baseados em biomoléculas: abordagens computacionais

“…17 É nesse contexto que as técnicas de MMC tiveram seu desenvolvimento estimulado. 18 13 Da Silva et al (2013, Deda et al (2013), Castro Bueno et al (2014). 14 Butt et al (1990).…”