Preparation of Highly Monodisperse Electroactive Pollen Biocomposites

Abstract

Sunflower pollen (SFP) was used as an ovel biotemplate to fabricate nanoporous and spiked particles coated with carboxyl-functionalized multiwalled carbon nanotubes (COOH-MWCNTs). The MWCNT coating on SFPs was characterized by scanning electron microscopy,d ynamic imaging particle analysis and Raman spectroscopy. The electrical properties of MWCNT-coated SFPs offer great potential tod evelop highly functional materials for electronics and optical applications.With continued innovations in materials science, robust biocompatible composites have received much attention due to their tailorable and multifunctional physical and chemical properties that enable promising applications in supercapacitors, polyactuators, catalysis, electronic sensors, biosensors and bioimaging.[1] In particular,e lectroconductivec omposites combining carbon materials and biopolymers with ah ierarchical structureh ave been reported to have excellent electrical conductivity and mechanical properties compared with nonfunctionalized biopolymers.[2] For example, Yang and co-workers reported the synthesis of polyphenylene sulfide-nanotube compositesb yasimple mixing and compression method, yielding am aterial which exhibitede nhanced conductive properties. [3] Presently,anumber of methods, such as covalent functionalization and noncovalent modification, are availablet or ealize carbon-based polymer composites with excellent mechanical and conductive performances. [1b, 4] However,t he synthesis of electroconductiveb iocompatible composite materials by as imple method remainsatechnological challenge.Nature offers variouse xcellent biotemplates with precise widths and lengths and uniform geometries, such as diatoms, yeasts, butterfly wings and pollen grains.[5] Above all, pollen grains are attracting significant attention owing to their nontoxicity, high surface area andl arge pore volumes. These uniquem icrostructures have inspired researchers to develop av ariety of applications such as supercapacitors, [6] lithiumi on batteries [7] and gas sensors. [8] Moreover,the carbon-based polymer additivesw ith the greatest potentiala re carbon nanotubes (CNTs).[9] Key attributes of CNTsi nclude intrinsically large surfacea reas and intriguing electrical properties that are motivating the development of new industrial products.[10] CNTs have become one of the main additives in polymer-composite fabrication because they are easy to produce and inexpensive.[11]Herein, we describe au nique method for preparing electroactive sunflower pollen (SFP) grains based on high-efficiency surfacef unctionalization with carboxyl-functionalized multiwalled CNTs( COOH-MWCNTs ). We introduce sodium dodecyls ulfate (SDS) into the precipitation process in order to endow hydrophilic chains on the surfaceo ft he pollen grains that serve as surfactants to enhanceh ydrophilic properties. SFP is used as an ovel biotemplate material to fabricate nanoporous and spikede lectroactive microspheres. The fabrication process and control of each step are shown in Figure 1(a, b)....

Pollen‐Based Magnetic Microrobots are Mediated by Electrostatic Forces to Attract, Manipulate, and Kill Cancer Cells

“…Since they are abundant in nature, biodegradable, [26][27][28] and monodisperse. [29,30] In addition, pollen microparticle shows enhanced structural stability [31] thanks to the sporopollenin outer sheath that can even resist the fossilization process. However, the hollow internal shells of pollen microparticles can be used for cargo encapsulation and delivery recently reported by our previous research.…”

An Intrinsically Micro‐/Nanostructured Pollen Substrate with Tunable Optical Properties for Optoelectronic Applications

“…[ 30,31 ] Several material science applications of pollen grains have been reported such as drug carriers, 3D scaffolds, pressure sensors, and oil‐absorbing sponges. [ 32–37 ] Recently, simple methods based on incubating pollen grains in alkaline solutions and that require minimal processing have been developed to transform hard pollen grains into flexible microgel and paper structures. [ 30,38 ] There remains an outstanding need to characterize and rationally tune the optical properties of pollen‐derived materials and to explore their potential suitability as photonically active substrates with distinct design principles compared to existing natural material substrates that are based on entangled network architectures.…”

Omnidispersible Hedgehog Particles with Multilayer Coatings for Multiplexed Biosensing

“…Star-like particles with modest corrugation are known to have other remarkable properties that strongly differentiate them from particles with smooth surfaces. − These properties include concentration of the electrical field at their apexes, lock-and-key assembly patterns, , catalytic activity related to topographic features, as well as enhanced intracellular delivery . These properties are expected to be retained in HPs and can be combined with omnidispersibility, enhancing the technological prospects of these engineered multiscale colloids.…”