A biofunctionalizable ink platform composed of catechol-modified chitosan and reduced graphene oxide/platinum nanocomposite

Abstract

We present an ink platform for a printable polymer–graphene nanocomposite that is intended for the development of modular biosensors. The ink consists of catechol-modified chitosan and reduced graphene oxide decorated with platinum nanoparticles (rGO–Pt). We modified the chitosan with catechol groups, in order to obtain adhesive properties and improve solubility. Dispersions of rGO–Pt in ethylene glycol were admixed with an aqueous solution of modified chitosan to yield an ink that is suitable for non-contact piezoelectric printing using a commercial microplotter (Sonoplot GIX Microplotter Desktop). As a proof of concept, printed patterns were biofunctionalized with DNA oligonucleotide probes for Streptococcus agalactiae (Group B streptococcus) using glutaraldehyde as a linker. Confocal microscopy revealed the successful hybridization of complementary polymerase chain reaction (PCR) products and low non-specific binding. Our results demonstrate that catechol-modified chitosan/rGO–Pt nanocomposites can be used as inks for piezoelectric printing and facilitate the attachment of biorecognition elements for biosensor applications.

A reproducible extrusion printing process with highly viscous nanoparticle inks

“…Inks with very low viscosities can be printed without application of an external force for ink transfer by surface force driven capillary printing (CP) [25]. Ultrasonic plotting (UP) provides a fluid pumping force actuated by ultrasonic vibrations of the nozzle and thus, permits a broader viscosity range (up to 450 mPa s) [32,33]. Extrusion printing (EP), often referred to as direct ink writing [34] or omnidirectional printing [35] can be adapted to very high ink viscosities (from about 1 mPa s to 10 6 mPa s) [24] and is the most important fluidfilament printing technology applied in printed electronics.…”

A platform for functionalization of cellulose, chitin/chitosan, alginate with polydopamine: A review on fundamentals and technical applications

“…The favourable suppression of oxidation and availability of non-oxidized CA at low pH conditions is required to enhance the adhesion, in contrast with the oxidation at higher pH leading to the formation of catechol-quinone intermediates and inter-/intramolecular amide adducts. Besides the good balance of adhesive and cohesive properties, the CA-chitosan was employed as biomedical materials with mucoadhesive properties [200], as bio-inks during complexation with serum proteins and metal ions [201], or in combination with reduced graphene oxide and platinum nanoparticles for biosensing [202].…”

Advantages of Graphene Biosensors for Human Stem Cell Therapy Potency Assays

“…Parameters of printing deposition for graphenic formulations that retain optical and electronical qualities [ 99 ] and the possibility of depositing ultralow friction graphene flakes [ 100 ] remain compatible with standards for of cell laden bioinks and 3D printing techniques [ 101 ]. Incorporation of compatible nanocomposite materials such as chitosan provides an ink platform suitable for the development of modular biosensors [ 102 ]. Technological progress for sensors allowing single use [ 103 ] or label-free measurement [ 104 ] combined with use of sustainable platforms such as paper [ 105 ] renders point-of-care use concepts feasible.…”