Ultrasensitive Bisphenol A Field-Effect Transistor Sensor Using an Aptamer-Modified Multichannel Carbon Nanofiber Transducer

Abstract

Bisphenol A (BPA) is a known endocrine-disrupting compound (EDC) that has a structure similar to that of the hormone estrogen. Even low concentrations of BPA are able to bind estrogen receptors, thereby inducing severe diseases such as reproductive disorders, chronic diseases, and various types of cancer. Despite such serious effects, the use of BPA remains widespread. Therefore, monitoring of both dietary and nondietary exposure to BPA is important for human healthcare. Herein, we present a field-effect transistor (FET) sensor using aptamer-modified multichannel carbon nanofibers (MCNFs) to detect BPA. The MCNFs are fabricated via single-nozzle electrospinning of two immiscible polymer solutions followed by thermal treatment in an inert atmosphere. The MCNFs are then oxidized using a solution of HNO3 and H2SO4 to introduce carboxyl groups on the surface of the fibers. The carboxyl-functionalized MCNFs (CMCNFs) are immobilized on an amine-functionalized electrode substrate by forming a covalent bond, and amine-functionalized BPA-binding aptamers are modified in the same manner on the CMCNFs. The resulting FET sensors exhibit a high sensitivity, as well as specificity toward BPA at an unprecedentedly low concentration of 1 fM. Furthermore, these sensors are stable and could be reused for repeated assays.

Aptamer-Based Carboxyl-Terminated Nanocrystalline Diamond Sensing Arrays for Adenosine Triphosphate Detection

“…First, dV/I d increases because of the negative charge of the NCD surface originating from the supporting DNA backbone. When the supporting DNA becomes double stranded by coupling with the aptamer, the negative charge in the channel area doubles and the current at the gate area increases [ 35 , 38 ]. The negative charge of the channel depends on the negative charge originating from the DNA backbone.…”

Predicting Future Prospects of Aptamers in Field-Effect Transistor Biosensors

“…In their report, Hagen et al exploited conformational change of aptamers after binding riboflavin, carrying their negative-charged phosphodiester backbones closer to the surface of the FET channels and inducing signal variation. Detection of adenosine triphosphate (ATP), bisphenol A (BPA), and β-estradiol by FET aptasensors was also accomplished [121][122][123][124][125] (publications fabricating FET aptasensors to detect small molecules are listed in Table 1). More recently, Nakatsuka and his colleagues depended on a similar strategy for successfully sensing serotonin, dopamine, glucose and sphingosine-1-phospate (S1P) by stem-loop aptamers and FET in a physiological environment [126].…”

Recent Advances in Electrospun Nanofiber Interfaces for Biosensing Devices

“…The most common methods proposed to generate bioreceptor-NF hybrid assemblies consist in the attachment of the biomolecules onto the fiber surface by physical or chemical sorption, covalent binding, cross-linking or entrapment in a membrane. This approach has been extensively used to immobilize enzymes [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], antibodies [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], DNA strands [ 71 , 72 , 73 ] and aptamers [ 74 , 75 ]. Another way to proceed, more specifically developed for enzyme biosensors, consists in entrapping the bioactive molecules inside the NFs by electrospinning a blend of enzymes and polymer [ 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , ...…”