Table 1.

Cellphone-based devices (CBD) for bioanalytical sciences.

Bioanalytical application	Type of CBD	Developed By	Characteristics	Reference
Immunoassays	• Cellphone-based CRP detection	Dublin City University, Ireland	LOD of the developed hsCRP assay was 0.026±0.002 μg/mL.	[3]
	• Cellphone-based detection of gold nanoparticle-labeled microfluidic immunoassay for human IgG	Chinese Academy of Sciences, China	The results of this on-chip immunoassay between anti-human IgG and human IgG were amplified by gold nanoparticle-enhanced staining and showed good correlation with hIgG concentration.	[4]
	• Cellphone-based personalized food allergen testing platform called iTube	UCLA, USA	Employs a light-weight, compact and cost-effective opto-mechanical attachment and a smart application that processes raw camera images within <1s. Detects allergen concentration in 20 min with a LOD of ~1 ppm.	[5]
	• Cellphone-based Escherichia coli detection platform	UCLA, USA	Employs a low-cost attachment, anti-E.coli O157:H7 antibody-functionalized capillary array and a quantum dot (QD)-based sandwich immunoassay. An LOD of ~5–10 cfu/mL is achieved for E.coli in water and milk samples.	[6]
	• Cellphone-based disposable immunoassay for diagnosing prostate cancer in urine using the PCADM-1 biomarkers	GENTAG, Inc. and MacroArray Technologies, LLC, USA	Non-invasive and highly cost-effective	[7]
Lateral flow assays	• CBD for quantitative detection of thyroid stimulating hormone (TSH)	University of Arizona, USA	Detects TSH in <12 min with an LOD of 0.31 mIU L−1 using Mie scatter optimized lateral flow assay. Processing is done using an external PC.	[8]
	• Cellphone-based Integrated rapid-diagnostic-test (RDT) reader	UCLA, USA	Compact, light-weight and cost-effective; powered by external or cellphone battery; employs a smart Android application to digitally process raw cellphone images within <0.2 s to create a diagnostic report (for e.g., HIV, malaria, etc.).	[9]
	• Cellphone-based rapid lateral flow test reader	Mobile Assay, Inc., USA	Employs mobile image ratiometry (MIR) to quantify rapid lateral flow test strips in 5–10 min. Detects cocaine and benzoylecgonine in the concentration range of 0.1–300 ng/mL and 0.003–0.1 ng/mL, respectively.	[10–12]
Electrochemical biosensing	• Compact cellphone platform-based electrochemical sandwich immunoassay for the detection of PfHRP2 biomarker for malaria	UCLA + Michigan State University, USA	Assay duration 15 min, LOD 16 ng/mL, employs a compact embedded circuit, disposable microfluidic chips and use of capillary flow.	[15]
	• iHealth Wireless Smart Gluco-Monitoring System	iHealth Lab Inc., USA	Saves up to 500 blood glucose test results wirelessly, track the trends, set up medication alerts and warns the user about the expiry of test strip.	[16]
	• Cellphone-based technology using the audio jack interface of iPhone to communication with point-of-care devices	Progical LLC, USA	Demonstrated the operation of OneTouch® UltraMini® glucose meter using an iPhone.	[17]
	• Cradle-configured interface between blood glucose meter and modem	North America technology Services, Inc., USA	Employs a multi-electrical contact-containing battery door that enables automatic download of blood glucose data (stored in the glucose meter) to an internal modem within a meter cradle and the data transmission to a central facility.	[18]
	• Cellphone-based transdermal glucose monitoring system using disposable skin patches with wireless sensors	GENTAG, Inc., Georgetown University and Science Applications International Corporation, USA	Each patch can be used for >100 glucose measurements over an extended period of time. It obviates the finger-pricking technology as the interstitial fluid is withdrawn by applying heat that ablates the stratum corneum.	[7]
Surface plasmon resonance-based biosensing	• Cellphone-based angle-resolved SPR detection system	Linkoping University, Sweden	LOD 0.1 μg/mL for the detection of β microglobulin; negligible non-specific binding; disposable; uses the conditioned illumination by cellphone's screen; and, SPR signal detection by the front camera of cellphone.	[21]
Microscopy	• Cellphone-based light microscope, integrated with a smart application for automated image analysis, for brightfield and fluorescence microscopy	UC Berkeley, USA	Clinical imaging of P. falciparum-infected and sickle RBC in brightfield imaging mode and M. tuberculosis-infected sputum samples in fluorescence imaging mode.	[22]
	• Cellphone-based optical microscope and visible-light spectrophotometer.	UC Davis, USA	Cellphone microscope has transmission and polarized microscopy modes, resolution of 1.5 μm over an imaging field of view of ~150 × 150 μm. Cellphone spectrophotometer has a bandwidth of 300 nm with a spectral resolution of ~5 nm.	[23]
	• Lensfree holographic cellphone microscope	UCLA, USA	USB-powered stand-alone unit; light-weight and compact (4.2 × 4.2 × 5.8 cm); CMOS image sensor; spatial resolution of ~1.5 μm over a FOV of ~24 mm2. Demonstrated imaging of micro-particles, WBCs, RBCs, platelets and waterborne parasites.	[25]
	• Lensfree holographic pixel-super resolution microscope	UCLA, USA	Submicron resolution over a large imaging FOV (~24 mm2). Demonstrated imaging of malaria infected blood samples.	[27]
	• Cellphone-based wide-field fluorescent microscope	UCLA, USA	Cost-effective and compact; uses battery-powered LEDs and an additional lens. Demonstrated for imaging of labeled WBCs in whole blood samples and waterborne parasites in water.	[28]
Flow cytometry	• Cellphone-based optofluidic fluorescent imaging flow cytometer	UCLA, USA	Compact, light-weight and cost-effective; uses a low-cost lens, a plastic color filter and coin cell batteries; analyse large sample volumes of >0.1 mL; fluorescent resolution of ~2 μm.	[29]
	• Cellphone-based miniaturized and low-cost imaging cytometry platform for rapid and cost-effective blood analysis	UCLA, USA	Determines the density of RBCs and WBCs, and the hemoglobin concentration in blood. Requires minute sample (~10 μL); good analytical performance as shown by validation with Sysmex KN21 hematology analyser.	[30]
Colorimetric detection	• Cellphone-based technique for precise POC colorimetric measurements in commercially-available urine test strips and pH papers	University of Cincinnati and Air Force Research Laboratory, USA	Uses the chromaticity values to determine the analyte concentration, which partially compensates for the variation in lighting conditions.	[31]