Myoglobin- and Hydroxyapatite-Doped Carbon Nanofiber-Modified Electrodes for Electrochemistry and Electrocatalysis

Abstract

In this paper, a hydroxyapatite (HAp)-doped carbon nanofiber (CNF)-modified carbon ionic liquid electrode (CILE) was prepared and used for the investigation on the direct electrochemistry and electrocatalysis of myoglobin (Mb). HAp nanoparticles were mixed within a polyacrylonitrile (PAN) solution, and a HAp@PAN nanofiber was synthesized by electrospinning process, which was further controlled by carbonization at 800 °C for 2 h in a nitrogen atmosphere to get a HAp@CNF nanocomposite. Various techniques were used to check the physicochemical properties of HAp@CNF. Mb was mixed with a HAp@CNF dispersion solution and casted on the surface of CILE to obtain an electrochemical sensing platform. The direct electrochemistry of Mb on the modified electrode was checked when a pair of enhanced redox waves appeared, indicating the direct electron transfer of Mb. HAp@CNF exhibited high conductivity, good biocompatibility, and large surface area, which was beneficial for Mb immobilization. The modified electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid and sodium nitrite, which was further used to establish a new electroanalytical method. Real samples were analyzed by the proposed method with satisfactory results.

Electrospun Carbon Nanofibers as an Electrochemical Immunosensing Platform forVibrio choleraeToxin: Aging Effect of the Redox Probe

“…Electrospun CNFs used as the platform for the electrochemical immunosensors for cholera toxin in this work were obtained using the conventional electrospinning technique. , The fabrication of the electrochemical immunosensor [i.e., GCE modified with CNF, antibody (Ab), and bovin serum albumin (BSA)] adopted the conventional method of covalently linking the antibody onto the electrode platform. , The immunosensor (GCE–CNF–Ab–BSA) is ready to be used for the sensing of the antigen (Ag), also described as VCT. The various steps involved have been schematically represented in Figure (described in detail in the Experimental Section).…”

“…Electrospun CNFs were obtained using the conventional electrospinning technique. , In this work, electrospinning works were carried out using the KD Scientific model syringe pump (KD Scientific Inc., USA). Briefly, 2 g of PAN polymer was weighed, dispersed in 15 mL of 100% w/w DMF, and ultrasonicated for 20 min at room temperature to allow for a thorough dissolution.…”

Electrocatalysis by Heme Enzymes—Applications in Biosensing

“…Besides typical analytes, such as H 2 O 2 , nitrite, and TCA, globin biosensors have been developed for detection of artemisinin [136], nitromethane [275], and chloropropandiol [276]. Recently, Mb-based nitrite and TCA biosensors, relying on DET transduction schemes, have been characterized in acidic pH conditions [138,277,278]. A Mg-based MOF/AuNPs biosensor employing Mb was able to detect up to 18 mM nitrite (Table 1) [138].…”

Novel construction of carbon nanofiber/CuCrO2 composite for selective determination of 4-nitrophenol in environmental samples and for supercapacitor application

“…The two main peaks were Cu 2p 1/2 and Cu 2p 3/2 at 960.49 and 940.50 eV, corresponding with the spin-orbital splitting energy of about D Cu 2p ¼ 19.9 eV, in good accordance with the reported data of the CuCrO 2 phase. 30,43,44 These observed results indicated that Cu existed in the +1 oxidation state. In addition to that, the Cu spectrum exhibited two satellite peaks at 950.…”