Metal-Free All-Carbon Nanohybrid for Ultrasensitive Photoelectrochemical Immunosensing of alpha-Fetoprotein

Abstract

C can accept up to six electrons reversibly and show exceptional light absorption over the entire UV-vis spectrum, making it a potential photoactive probe for photoelectrochemical (PEC) bioassay. However, few successful works have been reported to apply fullerenes in PEC biosensing, partially because of the low electronic conductivity and poor interfacial interactions with targeted biomolecules. Herein, we report the addressing of these two obstacles by coupling high conductive graphite flake (Gr), graphene oxide (GO) with sufficient oxygen-containing functional groups, and an alkylated C (AC) into a metal-free all-carbon nanohybrid (AC-Gr-GO) via harnessing delicate noncovalent interactions among them through a facile mechanical grinding. It was revealed that the as-obtained AC-Gr-GO nanohybrid not only showed conspicuous enhancement of photocurrent up to 35 times but also offered rich anchors for bioconjugation. With detection of alpha-fetoprotein as an example, the AC-Gr-GO based PEC immunosensor demonstrated a broad linear detection range (1 pg·mL to 100 ng·mL) and a detection limit as low as 0.54 pg·mL, superior/competitive to PEC immunosensors for AFP in previous reports. By a proper reinforcement in conductivity and biointerface engineering, this work may provide a new way to use fullerenes as photoactive materials in more general PEC biosensing.

Development of an Efficient Immunosensing Platform by Exploring Single-Walled Carbon Nanohorns (SWCNHs) and Nitrogen Doped Graphene Quantum Dot (N-GQD) Nanocomposite for Early Detection of Cancer Biomarker

“…The bioconjugate was prepared by adding 2 mL of N-GQD@SWCNH dispersion (1 mg/mL) in phosphate buffer saline (PBS 0.01 M pH 7.4) containing 50 mM of N -hydroxysuccinimide (NHS) and 100 mM of 1-ethyl-3-(3-dimethyl amonopropyl) carbodiimide (EDC) . After that, the mixture was agitated with an ultrasonicator for 30 min under darkness at room temperature.…”

One‐Pot Synthesis of CoS2Merged in Polymeric Carbon Nitride Films for Photoelectrochemical Water Splitting

“…Polymeric carbon nitride (PCN) has attracted widespread interest as a kind of inexpensive and sustainable semiconducting material. Owing to its polymeric nature, PCN can be readily achieved in the form of films on conductive substrate and is therefore able to further the development of functional devices, [1] such as photoelectrochemical (PEC) cells, [2] electrochemiluminescence, [3] sensors, [4] and others. [5] PCN filmbased photoelectrode is a typical example, and its performance highly relies on the transfer of the photoexcitation charge along the films.…”

Electrochemical Sensing of α-Fetoprotein Based on Molecularly Imprinted Polymerized Ionic Liquid Film on a Gold Nanoparticle Modified Electrode Surface

“…Hence, to determine AFP concentration in human serum is extremely important for patients who suffer from liver cancer. To date, for measuring AFP with high performances, many immunoassay methods based on fluorescence spectroscopy [2,3], chemiluminescence [4,5], electrochemiluminescence [6,7], enzyme-linked immunosorbent assay [8], surface plasmon resonance [9], electrochemical immunosensing [10,11] and photoelectrochemical sensing [12,13] have been successfully developed. Although some of these methods can give good sensitivity and selectivity for meeting the requirements for AFP determination, they still need to overcome many obstacles, such as time-consuming or sophisticated instruments, etc.…”