Preparation of Fe3O4@PS/PDA-Au nanotubes for sensitive electrochemical detection of alpha-fetoprotein

Au-Fe3O4 decorated polydopamine hollow nanoparticles as high performance catalysts with magnetic responsive properties

“…By adding of the absorbance of the infrared absorption band between 3600 and 3100 cm −1 from N-H/O-H stretching vibrations of PDA [16], the peak at 1615 cm −1 from the super position of N-H bending and C-C stretching of aromatic components, the peak at 1475 cm −1 from the shearing vibration of amide N-H of PDA and the peak at 1307 cm −1 from the stretching vibration of the phenol in PDA [16,49,50]. The absorption bands at the wave numbers of 1395 and 816 cm −1 are ascribed to stretching vibrations and deformation of aromatic rings [16]. No distinct changes appeared after Au NPs deposition onto the Fe 3 O 4 hollow nanoparticles in figure 4(c).…”

“…Recent studies have used capping reagents and other supports such as polymers [6,7], carbon nanotubes [8], graphene [9] metal oxides [1,2], silica [1,10,11], and others [3,12] for improving the recovery efficiency. Among these methods, magnetic nanoparticles (MNPs) [13], especially Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs) [14], provide a very promising solution because they can be easily separated by an external magnet [15][16][17][18]. Briefly, there are two types of Au and Fe 3 O 4 NP nanocomposites; deposition of Au NPs and/or Fe 3 O 4 NPs onto the outer surface (shell) of the supports [8,19,20] or the use of Fe 3 O 4 NPs acting as a core in the center [21,22].…”

“…This coating step often involves the application of polymers, silica or others as sacrificing agents and a step of template removal is required [7,24,[30][31][32][33]. Only a few studies have reported that small size Fe 3 O 4 NPs (<20 nm) prepared by coprecipitation or thermal decomposition methods (without a template removal step) can be deposited onto the particle surface, but these need the assistance of other supports or complicated operating conditions [8,16,17].…”

Carboxyethylsilanetriol-Coated Magnetic Nanoparticles as an Ultrasensitive Immunoplatform for Electrochemical Magnetosensing of Cotinine

“…16 They can be functionalized by specific groups (e.g., −OH, −COOH, and −NH 2 ) with proper surface modification, making them suitable for further changes by the immobilization of various biological molecules for various uses. 17 Polyethyleneimine, 18 (3aminopropyl)triethoxysilane, 19 carboxyl-functionalized multiwalled carbon nanotubes (MWCNTs), 20 poly(acrylic acid), 21 polydopamine, 22 poly(L-cysteine), 23 graphene nanospheres, 24 and polystyrene 25 have been utilized as magnetic nanoparticle modification materials in the literature. In addition, magnetic nanoparticles form a disposable and biocompatible surface to capture the target analyte.…”

An Electrochemical Sandwich Immunosensor Based on Signal Amplification Technique for the Determination of Alpha-Fetoprotein

“…Common markers include luciferin, enzymes, radioisotopes, nanomaterials, and electronic dense substances. The label sensor is highly sensitive and specific, which has been widely used (Peng et al, 2018;Fu et al, 2019b;Ge et al, 2019;Ma N. et al, 2019;Hu et al, 2020;Ying et al, 2020). When technology enters the nano-era, a large number of nanomaterials were used in biosensors (Baghayeri et al, 2018;Feng et al, 2020;Hojjati-Najafabadi et al, 2020;Hou et al, 2020;Karimi-Maleh et al, 2020c).…”