# Nanomaterials for Healthcare Biosensing Applications
## 2 Carbon Allotrope-Based Nanomaterial Applications in Healthcare Biosensing
### Fullerene Nanomaterials
This was possible due to the \(\pi\)-\(\pi\) interactions between the sp\({}^{2}\)\(\pi\) electron cloud of fullerene and IL-CCE. A perfectly linear current-concentration profile was obtained in the range of 1.47-247.20 ng mL\({}^{-1}\) and the limit of detection was found to be 0.36 ng mL\({}^{-1}\) in real and aqueous samples. This study utilised fullerene as a nanomediator and a four-fold transduction was realised in comparison to an electrode with no C\({}_{60}\)-monoadduct immobilisation when evaluated by differential pulse anodic stripping voltammetry (DPASV) and cyclic voltammetry (CV) [57]. Mazloum-Ardakani and co-workers used a similar ionic liquid by replacing MIPs with antibodies to generate a label-free electrochemical immunosensor to detect tumour necrosis factor \(\alpha\) (TNF-\(\alpha\)) [50]. They modified graphite screen printed electrodes (GSPE) with a nanocomposite of fullerene and multiwalled carbon nanotubes (MWCNT) to entrap anti-TNF-\(\alpha\). The GSPE-C\({}_{60}\)-MWCNT-IL-anti-TNF-\(\alpha\) immunosensor demonstrated a detection range of 5.0-75 pg mL\({}^{-1}\) with a low detection limit of 2.0 pg mL\({}^{-1}\). Rather et al. exploited the electron affinity of C\({}_{60}\) nanorods (C\({}_{60}\)NRs) to covalently add N-H from nitrophenylene modified GCE (GCE-Ph-NH\({}_{2}\)) across its \(\pi\) bond to obtain an electrochemical sensor for the detection of paraben (endocrine disruptor) [26]. Following electrochemical reduction, a highly conductive sensor (ERC\({}_{60}\)NRs-NH-Ph-GCE) was obtained. This sensor was capable of  
Figure 5: Development of a fullerene–palladium–platinum alloy-based biosensor for the detection of \(\alpha\)2,3-sialylated glycans [56]. detecting ethylparaben (EP) from 0.01 to 0.52 uM with an LOD of 3.8 nM. Electrochemical impedance spectroscopy (EIS) and CV were used to study the electrocatalytic activity of the sensor [26]. Demirbakan and Sezginturk used C\({}_{60}\) as an immobilisation surface on GCE to link heat shock protein 70 antibody (anti-HSP70) with the help of an 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide/ N-hidroysuccinimide (EDC-NHS) mixture in order to fabricate a novel immunosensor for sensitive HSP70 detection [51]. This GCE-C\({}_{60}\)-anti-HSP70 sensor, using CV and EIS as measurement methods, could successfully detect HSP70 concentrations between 0.8 and 12.8 pg mL\({}^{-1}\). Barberis et al. employed a combination of fullerene and graphite to generate sensor-biosensor systems (SBs) for ascorbic acid (AA) recognition [52]. They coupled ascorbate oxidase (AOx) with the biosensor and made a comparison between C\({}_{60}\)-modified and C\({}_{70}\)-modified graphite. The investigation range evaluated using amperometric detections for the study was 0-20 uM. The detection limit was found to be 0.10 uM and 0.13 uM for SBs with C\({}_{60}\) and C\({}_{70}\) modifications, respectively. The C\({}_{60}\) modification enhanced the sensitivity of graphite electrode 1.2 times, whereas the C\({}_{70}\) increased it by 1.5 in comparison to unmodified graphite. The selectivity of fullerene-modified SBs was superior to that of nanotube-modified SBs, since fullerenes are capable of holding more AOx. Another study, coupling an enzyme with a biosensor system, involved the fabrication of an electrochemical glucose biosensor, where C\({}_{60}\) was used as a moderator for the direct electron transfer of glucose oxidase (GOx) on reduced graphene oxide (RGO) [58]. CV and amperometry _i-t_ were able to obtain a linear response for glucose detection in a concentration range of 0.1-12.5 mM with an LOD of 35 uM. A similar study for glucose biosensing replaced RGO with GCE and C\({}_{60}\) with hydroxyfullerene (HF) to promote linking and complex formation with GOx [55]. The GOx-HF nanocomposites were immobilised on GCE and protected with a membrane of chitosan (chit). CV and linear sweep voltammetry (LSV) proved that the GCE-GOx-HF-chit sensor was functional to measure glucose from 50 uM to 1.0 mM with an LOD of 5 \(\pm\) 1 uM. Shahhoseini et al.