Facile Synthesis of Poly (N‐isopropylacrylamide) Coated SiO₂ Core‐shell Microspheres via Surface‐initiated Atom Transfer Radical Polymerization for H₂O₂ Biosensor Applications

Abstract

In this study, inorganic/organic composites containing poly (N‐isopropylacrylamide) coated core‐shell SiO2 microspheres were prepared via surface‐initiated atom transfer radical polymerization (ATRP). The thermal responsive polymer, N‐isopropylacrylamide was treated with methanol, water and CuBr/CuBr2/1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) at room temperature to form PNIPAM@SiO2 microspheres. The as‐prepared PNIPAM@SiO2 microspheres were characterized by FT‐IR, TGA, XPS, SEM, TEM analyses. Hemoglobin (Hb) was immobilized onto the surfaces of PNIPAM@SiO2 microspheres via hydrophobic and π‐π stacking interactions. The as‐prepared Hb/PNIPAM@SiO2 electrode exhibits well‐defined redox peak at a formal potential of −0.38 V, validating the direct electrochemistry of Hb. The Hb immobilized composite film retained its bioelectroactivity without any significant loss of catalytic activity. The modified electrode detects H2O2 over a wide linear concentration range (0.1 μM to 333 μM) with a detection limit of 0.07 μM. This modified electrode also successfully detects H2O2 from food and disinfectant samples with appreciable recovery values, validating its practicality. We believe that PNIPAM@SiO2 composite has great potential to be used in the detection of H2O2 and development of other enzyme based biosensors.

Performance of graphitic carbon nitride nanosheets derived from liquid and thermal exfoliations towards the electrochemical reduction of nitrobenzene

“…The performance of the present GC/GNNS-S electrode towards the sensing of Nb was compared with the recently reported papers (Table S3, ESI†). 19,25–37 The inspection of Table S3 (ESI†) indicates that most of the reported sensors for Nb were based on nanocomposites. The preparation of these nanocomposites not only involves several steps but also adopts tedious procedures.…”

“…Further, the sensors fabricated from SSG-AuAg and EDAS/g-C 3 N 4 -Ag are expensive. 25,34 However, the fabrication of the present sensor based on GNNS-S is very easy involving simple procedures and very importantly it is less expensive. Besides, it showed the highest LOD in contrast to the papers listed in Table S3 (ESI†).…”

Facile preparation of superhydrophobic and oleophobic surfaces via the combination of Cu(0)‐mediated reversible‐deactivation radical polymerization and click chemistry

“…These applications include the immobilization of different adsorbents for separations and/or removal of different compounds, such as dyes, heavy metals, and bovine serum albumin, the immobilization of catalysts and enzymes for increasing thermal stability, enhanced activity and ease of recovery, the modification of membranes for control of selectivity and biofouling, and the fabrication of superhydrophilic and superhydrophobic surfaces (including sprayable superhydrophobic coatings) . Nanoparticles modified with polymers also have been used as sensors (e.g., to detect H 2 O 2 ), fabricating anti‐biofouling surfaces, and for the preparation of hemocompatible surfaces in order to prevent blood coagulation …”

Thermally Stable and Processable Organic-Inorganic Hybrid Material

“…The obtained materials were core shell-like structure and showed the good thermoresponsive property. It was suggested that they were applicable to the fields of biological and biomedical fields [19,20]. In another strategy, using sol-gel process was a sequence of numerous SiO2 particles embedded with PNIPAM particles at room temperature [20].…”