HIGH SENSITIVE GAS MICROSENSORS BASED ON SULFONATED CNTS AND CNTS/POLYANILINE MIXTURE

Autor/autori: Dr. ing. Ştefan-Ionuţ SPIRIDON, Dr. ing. Eusebiu Ilarian IONETE, Ing. Bogdan Florian MONEA

Rezumat: Un senzor este definit ca un dispozitiv care detecteaz o cantitate variabil, de obicei un stimul neelectric i o transform în semnale electrice care sunt înregistrate. Performanele de msurare sunt definite de caracteristicile de sensibilitate, selectivitate, precizie i stabilitate a senzorului. Din cauza gradului ridicat de selectivitate i sensibilitate, senzori electrochimici reprezint o metod analitic foarte promitoare. Utilizai în asigurarea condiiilor de siguran la locul de munc, în inginerie medical, analiz de mediu sau sectorul alimentar, senzorii ofer aplicaii în domenii largi de interes. Dezvoltarea senzorilor electrochimici bazai pe nanomateriale, reprezint un avantaj de amplificare a semnalului i o rezoluie înalt de detecie, datorit straturilor active de conductivitate superioare, stabilitate termic i rezisten la stres mecanic. Dou structuri de microsenzori de gaz, pe baza de nanotuburi cu un singur perete (SWCNT), au fost obinute i folosite pentru detectarea unor gaze diferite, cum ar fi CO, NH3, CO2. Pe o structur de electrod de aur interdigitizat au fost depozitate, ca straturi active nanotuburile de carbon sulfonate (s-CNT) i mixturi de nanotuburi de carbon (CNT) / Polianilin (Pani). MicrosenzoriI obinui, sunt caracterizai prin activitate electrochimic ridicat i prezint o stabilitate îmbuntit, reprezentând o soluie pentru un sistem eficient de senzori de putere mic, cu aplicabilitate practic în domeniul monitorizrii mediului, asistenei medicale, automatizarii, controlul proceselor industriale, etc.

Cuvinte cheie: microsenzori, nanomateriale, senzor electrochimic, monizarea mediului .

Abstract: A sensor is defined as a device which detects a variable quantity, usually a non-electric stimulus and converts it into electrical signals that are recorded. Measurement performances are defined by the sensitivity, selectivity, accuracy and stability characteristics of the sensor. Because of their high degree of selectivity and sensitivity, electrochemical sensors represent a very promising analytical method. Used in occupational safety, medical engineering, process measuring engineering, environmental analysis, food sector, they provide wide application fields of interest. Electrochemical sensors development based on nanomaterials, represent a signal amplification advantage and high detection resolution due to active layers superior conductivity, thermal stability and mechanical stress resistance. Two gas microsensors, based on SWCNT, were obtained and used for different gases detection, like CO, NH3, CO2. On an interdigitized gold electrode structure were deposited, as active layers, sulfonated carbon nanotubes (s-CNTs) and carbon nanotubes (CNTs)/Polyaniline (PANi) mixture, respectively. The obtained microsensors, characterized by high electrochemical activity and improved stability, could be a solution for an efficient low-powered sensor-system with practical application in the field of environmental monitoring, healthcare, automation, industrial process control, etc.

Keywords: microsensor, nanomaterials, electrochemical sensor, environmental monitoring. 1

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