Magneto-controlled flow-injection device for electrochemical immunoassay of alpha-fetoprotein on magnetic beads using redox-active ferrocene derivative polymer nanospheres

Hong

et al. 2021

ACS Appl. Nano Mater.

Multifunctional nanolabels with both facile signal amplification and high selectivity are essential for the sensitive determination of the vital tumor marker alpha fetoprotein (AFP). Here, we prepared an immunosensing nanolabel (Ab2-PDA-AF) for convenient AFP detection by grafting the detection antibody (Ab2) and the electroactive redox probe aminoferrocene (AF) onto polydopamine (PDA) nanospheres through Michael addition and Schiff base reactions. The electrochemical signal is dually amplified by the Ab2-PDA-AF nanolabels when the nanolabels are selectively bound to the electrode. The electrochemical signal can be first amplified by oxidizing AF of the Ab2-PDA-AF on the electrode. The signal can be further amplified by the redox reaction of PDA nanospheres with the linked AF/AF+ on the nanospheres. More importantly, the integration of AF-PDA-Ab2 favors a quick electron transfer between AF and PDA nanospheres. Redox probes of AF/AF+ are bonded to the nanolabels instead of dispersing in an electrolyte solution, thus decreasing the electron-transfer resistance and increasing the current signal. The interfacial kinetic analysis demonstrates that the charge-transfer resistance is decreased by 80% by using Ab2-PDA-AF nanolabels. The sensor displays a low detection limit of ca. 0.01 pg/mL, as well as excellent selectivity, reproducibility, and stability. The linear calibration plot of the AFP immunosensor has been obtained in a range of 0.5–1000.0 pg/mL. The capability of the immunosensor has been verified by implementing the detection of AFP in human serum samples.

Section: Resultsmentioning

confidence: 66%

Multifunctional Nanolabels Based on Polydopamine Nanospheres for Sensitive Alpha Fetoprotein Electrochemical Detection

Hong

et al. 2021

ACS Appl. Nano Mater.

J of Applied Polymer Sci

“…Ferrocene and ferrocene derivatives have been focused on attributed to their unique applications such as electrochemistry, 10 biosensors, 10–11 molecular recognition, 11–12 catalysis, 13–14 fertilizers, 15 magnetism, 16 cancer treatment 17 and others 18–19 . Especially, ferrocene‐bearing polymers were of interest in the excellent combination of redox, mechanical, semi‐conductive, photo‐physical, and opto‐electronic properties 11,20–21 . For example, such ferrocene‐bearing polymer has been used as redox‐responsive drug release carriers, 22 highly efficient healing polymeric films, 23 ferrocene‐modified microgels optical devices, 24 nonvolatile resistive memory devices, 25 and flash memory devices, 26 magnetically switchable bio‐electrocatalytic system 27 and the like.…”

Section: Introductionmentioning

confidence: 99%

Electrospun nanofibers fromferrocene‐containingmultiblock copolymers prepared viaRAFTpolymerization withF127modified precursor

Zhou

Chao-feng

et al. 2021

Electrospun nanofibers from copolymers composed of ferrocene side chains and PEO100‐PPO65‐PEO100 (F127) were fabricated in chloroform and N,N–dimethyl formamide solutions (V/V = 95:5) at room temperature. Ferrocene‐containing multiblock copolymers (PFcMAn‐F127‐PFcMAn) were synthesized through reversible addition‐fragmentation chain transfer polymerization using s‐1‐dodecyl‐s''‐ (α, α'‐dimethyl‐α''‐acetic acid) trithiocarbonate (DDMAT) modified F127 with 2‐ (methacryloyloxy) ethyl ferrocencarboxylate (FcMA). The structures of as‐obtained chemicals were characterized by FTIR, 1H NMR, and 13C NMR. Additionally, the block copolymers molecular weight and polydispersity were measured using gel permeation chromatography. The electrochemical responsiveness of the polymers was investigated using cyclic voltammetry as well as the thermal stabilities of polymers and precursors were tested through DSC and TGA. The morphologies of electrospun fibers were observed through field emission scanning electronic spectroscopy and a fibrous diameter of 300–1100 nm was obtained. The results indicated that the suitable molecular weight of ferrocene ‐containing polymer would be processed in nanofibrous.

“…The motion of magnetic beads in microchannels driven by magnetic forces has been widely used in various applications for the manipulation of biological species, such as CTC sorting [17][18][19], DNA extraction [20] and antigen detection [21]. Targets carried by magnetic beads were captured at specific sites under the combined actions of the magnetic force and the fluid for further detections [22].…”

Section: Introductionmentioning

confidence: 99%

Deterministic Lateral Displacement-Based Separation of Magnetic Beads and Its Applications of Antibody Recognition

Zhang

Zeng

Han

et al. 2020

Sensors

This work presents a magnetic-driven deterministic lateral displacement (m-DLD) microfluidic device. A permanent magnet located at the outlet of the microchannel was used to generate the driving force. Two stages of mirrored round micropillar array were designed for the separation of magnetic beads with three different sizes in turn. The effects of the forcing angle and the inlet width of the micropillar array on the separating efficiency were studied. The m-DLD device with optimal structure parameters shows that the separating efficiencies for the 10 μm, 20 μm and 40 μm magnetic beads are 87%, 89% and 94%, respectively. Furthermore, this m-DLD device was used for antibody recognition and separation among a mixture solution of antibodies. The trajectories of different kinds of magnetic beads coupled with different antigens showed that the m-DLD device could realize a simple and low-cost diagnostic test.