Electrochemical Biosensors - Sensor Principles and Architectures

Abstract

Quantification of biological or biochemical processes are of utmost importance for medical, biological and biotechnological applications. However, converting the biological information to an easily processed electronic signal is challenging due to the complexity of connecting an electronic device directly to a biological environment. Electrochemical biosensors provide an attractive means to analyze the content of a biological sample due to the direct conversion of a biological event to an electronic signal. Over the past decades several sensing concepts and related devices have been developed. In this review, the most common traditional techniques, such as cyclic voltammetry, chronoamperometry, chronopotentiometry, impedance spectroscopy, and various field-effect transistor based methods are presented along with selected promising novel approaches, such as nanowire or magnetic nanoparticle-based biosensing. Additional measurement techniques, which have been shown useful in combination with electrochemical detection, are also summarized, such as the electrochemical versions of surface plasmon resonance, optical waveguide lightmode spectroscopy, ellipsometry, quartz crystal microbalance, and scanning probe microscopy.The signal transduction and the general performance of electrochemical sensors are often determined by the surface architectures that connect the sensing element to the biological sample at the nanometer scale. The most common surface modification techniques, the various electrochemical transduction mechanisms, and the choice of the recognition receptor molecules all influence the ultimate sensitivity of the sensor. New nanotechnology-based approaches, such as the use of engineered ion-channels in lipid bilayers, the encapsulation of enzymes into vesicles, polymersomes, or polyelectrolyte capsules provide additional possibilities for signal amplification.In particular, this review highlights the importance of the precise control over the delicate interplay between surface nano-architectures, surface functionalization and the chosen sensor transducer principle, as well as the usefulness of complementary characterization tools to interpret and to optimize the sensor response.

Katalaz Temelli PANI Biyosensörü ile Deltametrinin Belirlenmesi

“…Son yıllarda pestisitlerin CAT enzimini inhibe ettiğini gösteren birçok çalışma rapor edilmiştir [6,7,8,9]. Bu çalışmada da Deltametrinin CAT biyosensörünün aktivitesine etkisinin incelenmesi için 0.5-2.5 µM konsantrasyon aralığında olacak şekilde deltametrin reaksiyon hücresine ilave edildi ve CAT biyosensörü ölçüm almadan önce inhibisyon için bu ortamda 10 dk bekletildi.…”

“…Biyosensörler kolay hazırlanması, düşük maliyetli olması ve yerinde analize imkan vermesi nedeniyle çevre kirleticilerin analizinde GC, HPLC ve LC/MS/MS gibi klasik metotlara alternatiftirler. Özellikle enzim inhibisyonlarını temel alan biyosensör sistemleri bu amaca yönelik oldukça kullanışlı, ucuz, çabuk ve pratik sistemlerdir (6,7,8,9,10,11,12).…”

Properties and Customization of Sensor Materials for Biomedical Applications

“…Thanks to their high conductivity and large surface-to-volume ratio, small changes on the conformation or displacement of the immobilized bioreceptors can be detected (243,244). This transduction mechanism has been reported in field-effect transistors (FET) (2,69,245,246) and may provide the basis of future devices like sensor-based bioelectronic noses and tongues (114,236,247), although, at present, the response patterns obtained by these devices are not stable over time (2). This is a serious limitation in bioelectronic tongues and noses, although their potential to extract complex information from the sensor array seems very powerful (2).…”

Label-free affinity biosensor arrays: novel technology for molecular diagnostics

“…Much of the research to date has focused on the development and optimization of transducer materials, including a recent emphasis on carbon-based biosensors [3,4], and physiochemical transduction strategies, with transducers that are sensitive to the optical, electrochemical, and mechanical properties of biological molecules receiving most attention. A number of comprehensive review articles have been published that focus on biosensor transduction strategies [5][6][7]. There is also a significant body of work on optimized surface chemistries for antibody immobilization and alternative high-affinity binding agents such as antibody fragments, DNA and peptide aptamers, and molecularly imprinted polymers [8].…”