8 Bio-microelectromechanical Systems (BioMEMS) …
173
8.4 Alternative BioMEMS for Electrochemiluminescence
Detection
Arguably, the most crucial aspect of biosensor development is the immobilization
of the biorecognition or biomolecular elements onto an appropriate matrix. Alternation of the surface with biocompatible polymers, carbon-based nanomaterials, or
metal nanoparticles are amongst the most frequent ways to form selectively favorable surfaces for biomolecules (Holzinger et al. 2014; Buk et al. May 2017; Derkus
et al. 2014, 2015). Micro disk array electrodes represent a commonly studied microelectrode geometry for creating a steady-state current level (Buk and Pemble 2019).
In a novel study, electronics-standard lithography, deposition, and etching methods
were implemented to microfabricate gold micro disk array electrodes (GDAE) on Si
substrate. The electrodes were fabricated by utilizing standard Si/SiO 2 /metal microfabrication technology. Through this technology, to perform the patterning procedure
for the disk arrays the etching of a passivation layer was required that was deposited
on top of the metal layer. Each individual microelectrode composed of 85 gold disk
electrodes having 200 mm inter-electrode distance and 20 mm diameter and were
positioned hexagonally. A hybrid nano-material containing two distinctive types of
nanoparticles, carbon quantum dots (CQDs) and AuNPs were employed to modify
the gold electrode surfaces (Table 8.1). These particles offer favorable chemical
and physical characteristics which were used for fabrication of the miniaturized
biosensor for glucose detection. The electrodes were characterized electrochemically to examine the microfabrication route’s efficacy. Moreover, several immobilization methods were performed in order to prepare CQDs/AuNPs-GOx micro disk
array electrodes (Fig. 8.6). The principal components of the assay consist of GOx
(immobilized on the nanoparticles), phosphate buffer saline tablets, glucose, potassium chloride, sodium chloride, sulphuric acid, potassium ferrocyanide, cysteamin,
acetaminophen, and uric acid. The authors successfully developed a highly reliable and reproducible electrochemical biosensor that merges the utilization of the
miniaturized electrode technologies and CQDs/AuNPs nanohybrid materials. This
platform is suited for future development along the path of achieving an entirely onchip system, with potential further miniaturization, making it especially appealing
for a variety of applications (Buk and Pemble 2019).
NFO4 was used as the immobilized synthetic peptide to develop an amperometrics biosensor with high binding affinity. This study presented an application
of dual detection techniques applied into an electrochemical cell-on-a-chip (ECC)
microdisc electrode array, which showed great promises for further developments of
biosensors. The electrochemical ECC and bio-transducers were fabricated by lithography technique. A microdisc electrode array working electrode format was used for
this technique accompanied with microporous graphitized carbon (MGC) electrodeposited inside a poly (aniline-co-meta-aminoaniline) electroconductive polymer
layer (Table 8.1). As a redox mediator, iron-nickel hexacyanoferrate (Fe|NiHCF) was
deposited onto the MGC, amperometrically. Furthermore, the use of a Ni-FeHCF
layer enhanced the peroxide signal that would have been otherwise compromised
173
8.4 Alternative BioMEMS for Electrochemiluminescence
Detection
Arguably, the most crucial aspect of biosensor development is the immobilization
of the biorecognition or biomolecular elements onto an appropriate matrix. Alternation of the surface with biocompatible polymers, carbon-based nanomaterials, or
metal nanoparticles are amongst the most frequent ways to form selectively favorable surfaces for biomolecules (Holzinger et al. 2014; Buk et al. May 2017; Derkus
et al. 2014, 2015). Micro disk array electrodes represent a commonly studied microelectrode geometry for creating a steady-state current level (Buk and Pemble 2019).
In a novel study, electronics-standard lithography, deposition, and etching methods
were implemented to microfabricate gold micro disk array electrodes (GDAE) on Si
substrate. The electrodes were fabricated by utilizing standard Si/SiO 2 /metal microfabrication technology. Through this technology, to perform the patterning procedure
for the disk arrays the etching of a passivation layer was required that was deposited
on top of the metal layer. Each individual microelectrode composed of 85 gold disk
electrodes having 200 mm inter-electrode distance and 20 mm diameter and were
positioned hexagonally. A hybrid nano-material containing two distinctive types of
nanoparticles, carbon quantum dots (CQDs) and AuNPs were employed to modify
the gold electrode surfaces (Table 8.1). These particles offer favorable chemical
and physical characteristics which were used for fabrication of the miniaturized
biosensor for glucose detection. The electrodes were characterized electrochemically to examine the microfabrication route’s efficacy. Moreover, several immobilization methods were performed in order to prepare CQDs/AuNPs-GOx micro disk
array electrodes (Fig. 8.6). The principal components of the assay consist of GOx
(immobilized on the nanoparticles), phosphate buffer saline tablets, glucose, potassium chloride, sodium chloride, sulphuric acid, potassium ferrocyanide, cysteamin,
acetaminophen, and uric acid. The authors successfully developed a highly reliable and reproducible electrochemical biosensor that merges the utilization of the
miniaturized electrode technologies and CQDs/AuNPs nanohybrid materials. This
platform is suited for future development along the path of achieving an entirely onchip system, with potential further miniaturization, making it especially appealing
for a variety of applications (Buk and Pemble 2019).
NFO4 was used as the immobilized synthetic peptide to develop an amperometrics biosensor with high binding affinity. This study presented an application
of dual detection techniques applied into an electrochemical cell-on-a-chip (ECC)
microdisc electrode array, which showed great promises for further developments of
biosensors. The electrochemical ECC and bio-transducers were fabricated by lithography technique. A microdisc electrode array working electrode format was used for
this technique accompanied with microporous graphitized carbon (MGC) electrodeposited inside a poly (aniline-co-meta-aminoaniline) electroconductive polymer
layer (Table 8.1). As a redox mediator, iron-nickel hexacyanoferrate (Fe|NiHCF) was
deposited onto the MGC, amperometrically. Furthermore, the use of a Ni-FeHCF
layer enhanced the peroxide signal that would have been otherwise compromised