Table 1.
A comparison of the on-chip ultramicroelectrode glucose sensor, presented here with other reagent-free miniaturized enzymatic glucose biosensors, constructed towards various biomedical sensing applications.
| Electrode Material * | Linear Range | Operating Potential | Enzyme Immobilization | Sensitivity | Real Sample | Reference |
|---|---|---|---|---|---|---|
| CFM/Pt-GOx(0.5%)-GA | 0–4 mM | 0.7 V vs. Ag/AgCl (external RE) | Covalent | 0.697 nA mM−1 cm−2 | Brain slices | [48] |
| CF-PEDOT-GOx | 0.5–15 mM | −0.65 V vs. Ag/AgCl (external RE) | Entrapment | 8.5 μA mM−1 cm−2 | - | [49] |
| Pt/PEDGE/BSA-GOx | 0–5 mM | 0.85 V vs. Ag/AgCl (external RE) | Covalent | 20.72 pA mM−1 | Intracellular | [50] |
| Pt-B electrode | 0.2–43.5 mM | 0.7 V vs. Ag/AgCl (on-device) | Free in solution | - | Serum samples | [51] |
| Pt/PAA/CS/AuNPs/GOx | 0.017–0.81 mM | −0.4 V to 0.4 V to vs. Pt (on-device) | Layer-by-layer assembly | 61.4 μA mM−1 cm−2 | Saliva | [52] |
| Silver/Nafion/GA-GOx | 0–2 mM | 0.05 V vs. Ag/AgCl (external electrode) | Covalent | 1.73 μA mM−1 | - | [53] |
| Pt/GA-BSA-GOx/PU/Nafion | 0–11 mM | 0.5 V vs. IrOx (on-device) | Covalent | 1.51 nA mM−1 | Intradermal | [54] |
| GOx-β-cyclodextrin-o-PD/Pt-B/Au | 2.5–15 mM | 0.25 V vs. Pt (on-device) | Entrapment | 111.21 µA mM−1 cm−2 (Buffer), 15 µA mM−1 cm−2 (Serum) | Fetal bovine serum | This work |
* Abbreviations: CFM: carbon fibre microelectrode, Pt: platinum, GOx: glucose oxidase, GA: glutaraldehyde, CF: carbon fibre, PEDOT: poly (3, 4-ethylenedioxythiophene), PEDGE: poly (ethylene glycol) diglycidyl ether, BSA: bovine serum albumin, PAA: poly (allylamine), CS: chitosan, AuNPs: gold nanoparticles, and PU: polyurethane.