Table 2.

Selected biosensors of various signal detection methods that are commonly used in WBE to detect various pathogens and infectious diseases.

Signal detection methods	Advantages	Limitations	Infectious diseases / pathogens	Ref
Electrochemical (Voltammetric, Amperometric, Potentiometric)	•Low LOD, •High sensitivity, •Fast response time, Low cost, can be miniaturized with other portable devices	Potentiometric has issues related to immobilization, poor linear range, low reproducibility potential	•Hepatitis A virus (HAV) •Hepatitis viruses (types A-E) •Rotavirus	[[144], [145], [146]]
Optical (Fluorescence, Luminescence, Colorimetry)	•Selective, High sensitivity, Real-time,	Complex, High cost, Bulky equipment (not portable), relatively high LOD	•Adenovirus •Enterovirus 71 (EV71) •Bovine viral diarrhoea virus	[[147], [148], [149]]
Piezoelectric	•Label-free, •Rapid, Simple, Low cost, •High sensitivity	Long incubation times, difficulties in regenerating crystal surfaces, multiple washing and drying steps, difficult to immobilize the antibodies on quartz crystal	•Rotavirus and adenovirus •Hepatitis viruses type A and type B	[139,140]
Microfluidics	•Multiple biosensings (LAMP, PCR), Relatively high sensitivity, Portable, Can be combined with many detection tools (optical, electrochemical), Can be integrated with paper-based devices and functional nanomaterials	Requires in-depth study on functional materials to simplify device, not miniaturize enough	•RNA viruses • E. coli •Bacteria (E. coli, Salmonella, and Pseudomonas) and viruses (MS-2 and •Echovirus)	[141,150,151]
Paper-Based Devices	•Simple process, •Low cost, Portable, can be integrated with microfluidic system and functional nanomaterials	Challenge to deal with complex WBE matrix	•Norovirus •E.Coli •Malaria	[[152], [153], [154]]