Table 1.

Electrochemical biosensors: types, materials, and methods.

Types of Biosensors	Measurement Methods	Sampling Methods	Fabrication Material	Fabrication Methods
Platforms	Impedance Potentiometry Amperometry (enzymatic) Voltammetry (non-enzymatic)	Vacuum Capillary Swelling	Polymers Silicon	Laser ablation Laser cutting
Solid MNs	Impedance Potentiometry Amperometry (enzymatic) Voltammetry (non-enzymatic)	Compression Absorption Vacuum	Silicon Ceramics Glass Metals	Laser ablation Laser cutting Casting Electroplating Lithography Wet and dry etching methods Metal injection molding Micromolding Two photon polymerization
Coated MNs	Impedance Potentiometry Amperometry (enzymatic) Voltammetry (non-enzymatic)	Capillary	Silicon Metals	Micromolding Dip coating Spray coating Layer-by-layer manufacturing
Dissolving MNs	Impedance Potentiometry Amperometry (enzymatic) Voltammetry (non-enzymatic)	Swelling	Cellulose Carbohydrates Sodium carboxymethyl	Mold based techniques Drawing lithography UV assisted fabrication Heat Droplet air blowing Fused deposition modeling Atomized spray process
Hollow MNs	Impedance Potentiometry Amperometry (enzymatic) Voltammetry (non-enzymatic)	Capillary Vacuum	Silicon Ceramics Polymers Glass Metals	MEMS Deep reactive ion etching Photolithographic Micromachining Pipette technique Deep X-ray lithography

MN: microneedle.