کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
596674 1454051 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Silicon oxide surface functionalization by self-assembled nanolayers for microcantilever transducers
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Silicon oxide surface functionalization by self-assembled nanolayers for microcantilever transducers
چکیده انگلیسی

We developed a functionalization procedure for silicon oxide surfaces used in microcantilever-based sensors dedicated to the detection of food contaminants in fluid matrices. In particular we focused on the determination of heavy metal ions and of agricultural pesticides. The surface functionalization was obtained by direct self-assembly of long chain molecules bearing at one end a complexing moiety for metal ions. The selected chelating molecule, the nitrilotriacetic acid (NTA), was immobilized onto silicon oxide surfaces using a three-step process involving the consecutive addition of an organosilane, glutaraldehyde and a NTA derivative solutions. The formation of the self-assembled nanostructure (SAN) at the surface was traced by means of quartz crystal microbalance with dissipation monitoring (QCM) measurements as a function of time. The results indicated that the functionalized molecule forms a rigid self-assembled film on silicon dioxide. Data analysis provided the layer thickness and the molecular orientation of the chemisorbed layers at the interface. The optimized procedure was tentatively applied to functionalize the silicon oxide outer surface of an array of microwells each containing four microcantilevers. Quantitative determination of the metal ions complexation at the surface was achieved adding the desired solution in the QCM measuring chamber and recording the adsorbed mass change as a function of concentration.The above self-assembled system was further exploited for the detection of pesticides in fluid matrices monitoring the variation in the QCM signal upon addition of the analyte in the measuring chamber.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 321, Issues 1–3, 15 May 2008, Pages 87–93
نویسندگان
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