Smartphone-based Device Research Articles

Enhancing anti-interference ability of molecularly imprinted ratiometric fluorescence sensor via differential strategy demonstrated by the detection of bovine hemoglobin

The non-specific adsorption of interferents onto the outside surface of molecularly imprinted polymers (MIPs) particles is disadvantageous for selective determination of the template molecules. Based on the fact that the responses of non-imprinted polymers (NIPs) and MIPs particles to non-template molecules are similar, the anti-interference ability of MIPs sensor can be much improved via differential strategy, demonstrated by bovine hemoglobin (BHb) determination. The MIPs for BHb were prepared via surface imprinting and sol-gel process, with graphene quantum dots@SiO2/CdTe quantum dots (GQDs@SiO2/CdTe QDs) for ratiometric fluorescence measurements. By using a weight factor of 1.283 to compensate the lower specific surface area in NIPs particles, the differential ratiometric fluorescence signals between MIPs and NIPs channels to 2.00 μM ovalbumin and phycocyanin are equivalent to BHb at the concentration of 0.025 and 0.014 μM, which are only about 11 % and 5.8 % of the interference level in the normal ratiometric fluorescence method, respectively. The differential ratiometric fluorescence measurement was also performed in a smartphone-based device for field analysis of BHb in urine samples, with the linear range of 0.05–4 μM and the detection limit of 13 nM.

Portable smartphone-based device for on-site detection of Hg2+ in water samples

ABSTRACT In this paper, a smartphone-based portable device was designed for on-site and real-time detection of Hg2+ concentration levels in water samples. A rhodaminespirolactam-based derivative3ʹ,6ʹ-bis(diethylamino)-2-((3,4,5-trimethoxybenzylidene)amino)spiro[isoindoline-1,9ʹ-xanthen]-3-one, which had selective response to Hg2+,was used as Off-On fluorescent probe. The enhanced emission was observed by a high-pixel camera integrated on the smartphone. The grey value was analysed by an android/apple application ‘Detection’, and showed good linearly with Hg2+ concentration ranged from 0.01 to 0.1 μg/ml. The limit of detection (LODs) was found at 0.9 μg/l, which was sensitive enough to detect Hg2+ in industrial wastewater and drinking water. The accuracy of the proposed method was validated by reference Hg2+ solution, and the result was in good agreement with the certified value. Compared with cold vapour atomic fluorescence spectrophotometry, atomic absorption spectrophotometry methods and fluorescence method, etc., the developed platform is simpler, cost-less and portable for on-site and real-time application, and can be used for sharing of in-field sensing data from any remote location to the central water quality monitoring station.

Clinical evaluation of smartphone-based fluorescence imaging for guidance and monitoring of ALA-PDT treatment of early oral cancer.

.Significance: India has one of the highest rates of oral cancer incidence in the world, accounting for 30% of reported cancers. In rural areas, a lack of adequate medical infrastructure contributes to unchecked disease progression and dismal mortality rates. Photodynamic therapy (PDT) has emerged as an effective modality with potential for treating early stage disease in resource-limited settings, while photosensitizer fluorescence can be leveraged for treatment guidance.Aim: Our aim was to assess the capability of a simple smartphone-based device for imaging 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence for treatment guidance and monitoring as part of an ongoing clinical study evaluating low-cost technology for ALA-based PDT treatment of early oral cancer.Approach: A total of 29 subjects with diameter moderately/well-differentiated microinvasive ( depth) oral squamous cell carcinoma lesions (33 lesions total, mean area ) were administered ALA in oral solution and imaged before and after delivery of total light dose to the lesion surface. Smartphone-based fluorescence and white light (WL) images were analyzed and compared with ultrasound (US) imaging of the same lesions.Results: We present a comparative analysis of pre- and post-treatment fluorescence, WL, and US images of oral lesions. There was no significant difference in the distribution of lesion widths measured by fluorescence and US (mean widths of 14.5 and 15.3 mm, respectively) and linear regression shows good agreement (). In general, PpIX fluorescence images obtained prior to therapeutic light delivery are able to resolve lesion margins while dramatic photobleaching () is visible post-treatment. Segmentation of the photobleached area confirms the boundaries of the irradiated zone.Conclusions: A simple smartphone-based approach for imaging oral lesions is shown to agree in most cases with US, suggesting that this approach may be a useful tool to aid in PDT treatment guidance and monitoring photobleaching as part of a low-cost platform for intraoral PDT.

Portable and Field-Ready Detection of Circulating MicroRNAs with Paper-Based Bioluminescent Sensing and Isothermal Amplification.

We present a paper-based system that integrates bioluminescence resonance energy transfer (BRET) and isothermal amplification for the analysis of tumor-associated circulating microRNAs (miRNAs) in clinical serum samples. The analysis procedure could be easily accomplished with two pieces of functionalized paper and a low-cost smartphone-based device, which enables sequence-specific quantification of femtomolar miRNAs, without the need for tedious handling of aqueous reactions and operation of sophisticated equipment. Furthermore, the analytical performance of the proposed paper-based system was highly stable at room temperature, demonstrating its capability for cold-chain-free and remote deployment. These qualities highlight the practical utility of our method for the portable and field-ready miRNA diagnostic tests in resource-limited settings.

Smartphone-Based Device for Non-Invasive Heart-Rate Measurement of Chicken Embryos.

Heart rate (HR) is an important parameter in the study of the developmental physiology of chicken embryos and a crucial indicator of dead or live embryo grading in artificial incubation processes. A non-invasive HR measurement technique is required for long-term and routine HR assessment with minimal influence on embryo development. Accordingly, in this study, a non-invasive HR measurement technique of chicken embryos using a smartphone is demonstrated. The detection method of the proposed device is based on the photoplethysmography principle in which a smartphone camera is used for video recording, and the chicken embryonic HR is obtained from the recorded video images using a custom Android application. We used a smartphone to measure the embryonic HR of 60 native chicken eggs and found that it can measure the chicken embryonic HR from day 4 to day 20. The proposed smartphone HR device will be beneficial for scientific research and industrial applications. With internet connectivity, users can utilize their smartphone to measure the HR, display, share, and store the results.

Denoising ECG Signal by CSTFM Algorithm: Monitoring During Motorbike and Car Races

mHealth technology, by using habitual devices, i.e., smartphones, improves prevention, diagnosis, treatment, monitoring, and management of health. Monitoring heart profile during intense sports activities allows to diagnose pathologies, not identifiable with the traditional Holter approach and, therefore, it can help preventing possible injuries. On the other hand, denoising and extracting features from electrocardiographic (ECG) signal acquired during physical activity is a challenging task due to motion artifacts and measurement noise. In this paper, we propose a solution enabling a complete analysis of ECG signal through the implementation of a robust denoising algorithm, which has been characterized on synthetic signals and then has been tested on real traces acquired with a low-cost smartphone-based device during motorbike and car races.

Comparison of a Smartphone-Based Photography Method with Indirect Ophthalmoscopic Assessment in Referable Retinopathy of Prematurity: A Smart Retinopathy of Prematurity Model Pilot Study

Abstract This study sought to evaluate the agreement between smartphone-based device assisted remote screening and gold standard indirect ophthalmoscopic examination in cases of referable Retinopathy of Prematurity (ROP).

Deep Learning Approaches to Detect Atrial Fibrillation Using Photoplethysmographic Signals: Algorithms Development Study.

BackgroundWearable devices have evolved as screening tools for atrial fibrillation (AF). A photoplethysmographic (PPG) AF detection algorithm was developed and applied to a convenient smartphone-based device with good accuracy. However, patients with paroxysmal AF frequently exhibit premature atrial complexes (PACs), which result in poor unmanned AF detection, mainly because of rule-based or handcrafted machine learning techniques that are limited in terms of diagnostic accuracy and reliability.ObjectiveThis study aimed to develop deep learning (DL) classifiers using PPG data to detect AF from the sinus rhythm (SR) in the presence of PACs after successful cardioversion.MethodsWe examined 75 patients with AF who underwent successful elective direct-current cardioversion (DCC). Electrocardiogram and pulse oximetry data over a 15-min period were obtained before and after DCC and labeled as AF or SR. A 1-dimensional convolutional neural network (1D-CNN) and recurrent neural network (RNN) were chosen as the 2 DL architectures. The PAC indicator estimated the burden of PACs on the PPG dataset. We defined a metric called the confidence level (CL) of AF or SR diagnosis and compared the CLs of true and false diagnoses. We also compared the diagnostic performance of 1D-CNN and RNN with previously developed AF detectors (support vector machine with root-mean-square of successive difference of RR intervals and Shannon entropy, autocorrelation, and ensemble by combining 2 previous methods) using 10 5-fold cross-validation processes.ResultsAmong the 14,298 training samples containing PPG data, 7157 samples were obtained during the post-DCC period. The PAC indicator estimated 29.79% (2132/7157) of post-DCC samples had PACs. The diagnostic accuracy of AF versus SR was 99.32% (70,925/71,410) versus 95.85% (68,602/71,570) in 1D-CNN and 98.27% (70,176/71,410) versus 96.04% (68,736/71,570) in RNN methods. The area under receiver operating characteristic curves of the 2 DL classifiers was 0.998 (95% CI 0.995-1.000) for 1D-CNN and 0.996 (95% CI 0.993-0.998) for RNN, which were significantly higher than other AF detectors (P<.001). If we assumed that the dataset could emulate a sufficient number of patients in training, both DL classifiers improved their diagnostic performances even further especially for the samples with a high burden of PACs. The average CLs for true versus false classification were 98.56% versus 78.75% for 1D-CNN and 98.37% versus 82.57% for RNN (P<.001 for all cases).ConclusionsNew DL classifiers could detect AF using PPG monitoring signals with high diagnostic accuracy even with frequent PACs and could outperform previously developed AF detectors. Although diagnostic performance decreased as the burden of PACs increased, performance improved when samples from more patients were trained. Moreover, the reliability of the diagnosis could be indicated by the CL. Wearable devices sensing PPG signals with DL classifiers should be validated as tools to screen for AF.

Smartphone-Based, Rapid, Wide-Field Fundus Photography for Diagnosis of Pediatric Retinal Diseases.

PurposeAn important, unmet clinical need is for cost-effective, reliable, easy-to-use, and portable retinal photography to evaluate preventable causes of vision loss in children. This study presents the feasibility of a novel smartphone-based retinal imaging device tailored to imaging the pediatric fundus.MethodsSeveral modifications for children were made to our previous device, including a child-friendly 3D printed housing of animals, attention-grabbing targets, enhanced image stitching, and video-recording capabilities. Retinal photographs were obtained in children undergoing routine dilated eye examination. Experienced masked retina-specialist graders determined photograph quality and made diagnoses based on the images, which were compared to the treating clinician's diagnosis.ResultsDilated fundus photographs were acquired in 43 patients with a mean age of 6.7 years. The diagnoses included retinoblastoma, Coats' disease, commotio retinae, and optic nerve hypoplasia, among others. Mean time to acquire five standard photographs totaling 90-degree field of vision was 2.3 ± 1.1 minutes. Patients rated their experience of image acquisition favorably, with a Likert score of 4.6 ± 0.8 out of 5. There was 96% agreement between image-based diagnosis and the treating clinician's diagnosis.ConclusionsWe report a handheld smartphone-based device with modifications tailored for wide-field fundus photography in pediatric patients that can rapidly acquire fundus photos while being well-tolerated.Translational RelevanceAdvances in handheld smartphone-based fundus photography devices decrease the technical barrier for image acquisition in children and may potentially increase access to ophthalmic care in communities with limited resources.

Rapid and selective detection of Fe (III) by using a smartphone-based device as a portable detector and hydroxyl functionalized metal-organic frameworks as the fluorescence probe

Here, a label-free fluorescent sensor was developed for detection Fe (III) by utilizing the quenching effect of Fe (III) on the fluorescence of the hydroxyl functionalized metal-organic framework MIL-53(Fe)-(OH)2, which was synthesized by using a one-step solvothermal method. The specific binding interaction between Fe (III) and hydroxyl facilitated the absorption of free Fe (III) to MIL-53(Fe)-(OH)2, which leads to rapid fluorescent intensity quenching effect. The potential quenching mechanism was proved to be the photo-induced electron transfer (PET) from electron-rich ligands of MIL-53(Fe)-(OH)2 to the half-filled 3d orbitals of free Fe (III) in the sample solution. For in-field applications, the fluorescence signal was detected rapidly by using a homemade 3D-printed, portable, and low-cost smartphone sensor. A commercial 365 nm UV LED light was adopted as the excitation light source, while the camera in a smartphone was utilized as the optical detector. The fluorescent signals obtained by using the smartphone sensor were in a good agreement with those obtained from a commercial microplate reader. Under the optimal assay conditions, the linear detection range of Fe (III) was 5.0–200 μM, and the limit of detection is 1.7 μM. This result is compatible with the commercial microplate reader. The developed method was successfully adopted to detect Fe (III) in human serum and environmental water samples with acceptable recovery values of 90–108.5%. The portable, low-cost, fast-response, user-friendly and sensitive fluorescent protocol based on a self-quenching fluorescent nanoprobe can be conducted at home or anywhere else without sophisticated instruments, showing a great application potential in clinical diagnosis, on-site environmental monitoring and healthcare at home.

Validation of Smartphone-Based Retinal Photography for Diabetic Retinopathy Screening.

Screening for diabetic retinopathy (DR) is cost-effective when compared with disability loss for those who go blind in the absence of a screening program. We aimed to evaluate the sensitivity and specificity of a smartphone-based device for the screening and detection of DR. A cross-sectional study of 220 patients with diabetes (440 eyes, all patients age 25 years or older) was completed. Tropicamide 0.5% was used for iris dilation followed by an indirect ophthalmoscopy using a 20-D lens. Retinal images were later obtained using a smartphone attached to an adaptable camera device. Retinal images permitted the visualization of the macular and papillary regions and were sent without compression via the internet to a retinal specialist for interpretation. Sensitivity and specificity were calculated for all cases and stages of DR. Using our standard examination method, the prevalence of DR and macular edema were 13.6% and 6.4%, respectively. With the smartphone-based retinal camera, the prevalence of DR and macular edema were 18.2% and 8.2%, respectively. Sensitivity and specificity for the detection of all stages of DR was 73.3% and 90.5%, respectively. For the detection of macular edema, sensitivity was 77.8%, and specificity was 95%. For severe nonproliferative DR (NPDR), sensitivity and specificity were 80% and 99%, respectively; for proliferative DR (PDR), they were both 100%. In the early stages of DR, specificity was 89.8% for mild NPDR and 97.1% for moderate NPDR. Sensitivity was 57.1% and 42.9%, respectively. Screening for DR using a smartphone-based retinal camera has a satisfactory specificity at all DR stages. Its sensitivity seems to be high only in the stages of DR necessitating a specific therapeutic decision (eg, macular edema, severe NPDR, and PDR). A smartphone-based retinal camera may be a useful device to screen for DR in resource-limited settings. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:S18-S22.].

Iron (III) determination in bioethanol fuel using a smartphone-based device

The presence of Fe(III) can catalyse fuel degradation processes, providing their inefficient burning and increasing the emission of harmful gases into the atmosphere. Thereby, Brazilian National Petroleum Agency establishes a strict limit for the maximum concentration of iron in fuel bioethanol (5 mg kg−1 that corresponds to 6.18 mg L−1), usually monitored by atomic absorption spectrometer. The main subject in this work was to determine the concentration of iron (Fe3+) in bioethanol fuel using the digital image method as a simple analytical methodology. Colorimetric determination was performed by Color Grab app in its RGB (red, green and blue) matrices, installed on a Smartphone. Fe(III) determination was based on its ability to complex with thiocyanate (SCN−) generating a red complex (Fe(SCN)2+). The correlation between Fe(III) concentration and color intensity was obtained after the transformation of RGB components into a grayscale model. A linear response was observed in the concentration range between 0.5 and 10 mg L−1 (R2 = 0.998) with a detection limit of 0.1 mg L−1. Recovery values between 97% and 105% were obtained for the analysis of spiked fuel bioethanol samples. The results agreed with those obtained by spectrophotometry. Repeatability (n = 10) of 2.1% and 1.3% was obtained for the determination of 1 and 4 mg L−1 of Fe3+, respectively. This work demonstrates that smartphone-based methods provide great promise for in-field fuel quality control.

Cardiac Triangle Mapping: A New Systems Approach for Noninvasive Evaluation of Left Ventricular End Diastolic Pressure

Noninvasive and practical assessment of hemodynamics is a critical unmet need in the treatment of both chronic and acute cardiovascular diseases. Particularly, the ability to monitor left ventricular end-diastolic pressure (LVEDP) noninvasively offers enormous benefit for managing patients with chronic congestive heart failure. Recently, we provided proof of concept that a new cardiac metric, intrinsic frequency (IF), derived from mathematical analysis of non-invasively captured arterial waveforms, can be used to accurately compute cardiovascular hemodynamic measures, such as left ventricle ejection fraction (LVEF), by using a smartphone. In this manuscript, we propose a new systems-based method called cardiac triangle mapping (CTM) for hemodynamics evaluation of the left ventricle. This method is based on intrinsic frequency (IF) and systolic time interval (STI) methods that allows computation of LVEDP from noninvasive measurements. Since the CTM method only requires arterial waveform and electrocardiogram (ECG), it can eventually be adopted as a simple smartphone-based device, an inexpensive hand-held device, or perhaps (with future design modifications) a wearable sensor. Such devices, combined with this method, would allow for remote monitoring of heart failure patients.

An inexpensive smartphone-based device for point-of-care ovulation testing.

The ability to accurately predict ovulation at-home using low-cost point-of-care diagnostics can be of significant help for couples who prefer natural family planning. Detecting ovulation-specific hormones in urine samples and monitoring basal body temperature are the current commonly home-based methods used for ovulation detection; however, these methods, relatively, are expensive for prolonged use and the results are difficult to comprehend. Here, we report a smartphone-based point-of-care device for automated ovulation testing using artificial intelligence (AI) by detecting fern patterns in a small volume (<100 μL) of saliva that is air-dried on a microfluidic device. We evaluated the performance of the device using artificial saliva and human saliva samples and observed that the device showed >99% accuracy in effectively predicting ovulation.

Experience of Emergency Department Patients With Using the Talking Pole Device: Prospective Interventional Descriptive Study.

BackgroundPatient engagement is important. However, it can be difficult in emergency departments (EDs).ObjectiveThe aim of this study was to evaluate the satisfaction of ED patients using a patient-friendly health information technology (HIT) device, the “Talking Pole,” and to assess the factors relevant to their satisfaction.MethodsThis study was conducted in May 2017 at the ED of a tertiary hospital. The “Talking Pole” is a smartphone-based device attached to a intravenous infusion pole with sensors. It is capable of sensing patient movement and fluid dynamics. In addition, it provides clinical information from electronic medical records to patients and serves as a wireless communication tool between patients and nurses. Patients and caregivers who entered the observation room of the ED were selected for the study. The “Talking Pole” devices were provided to all participants, regardless of their need for an intravenous pole upon admittance to the ED. After 2 hours, each participant was given an 18-item questionnaire created for this research, measured on a 5-point Likert scale, regarding their satisfaction with “Talking Pole.”ResultsAmong 52 participants recruited, 54% (28/52) were patients and the remaining were caregivers. In total, 38% (20/52) were male participants; the average age was 54.6 (SD 12.9) years, and 63% (33/52) of the participants were oncology patients and their caregivers. The overall satisfaction rate was 4.17 (SD 0.79 ) points. Spearman correlation coefficient showed a strong association of “overall satisfaction” with “comparison to the previous visit” (ρ=.73 ), “perceived benefit” (ρ=.73), “information satisfaction” (ρ=.70), and “efficiency” (ρ=.70).ConclusionsIn this study, we introduced a patient-friendly HIT device, the “Talking Pole.” Its architecture focused on enhancing information delivery, which is regarded as a bottleneck toward achieving patient engagement in EDs. Patient and caregiver satisfaction with the “Talking Pole” was positive in the ED environment. In particular, correlation coefficient results improved our understanding about patients’ satisfaction, HIT devices, and services used in the ED.

Home sperm testing device versus laboratory sperm quality analyzer: comparison of motile sperm concentration

To test the ability of the smartphone-based YO Home Sperm Test to accurately and precisely measure motile sperm concentration (MSC) versus the SQA-Vision, an automated laboratory semen analyzer. MSC compared for the YO device on Galaxy and iPhone smartphones versus the SQA-Vision in a double-blind manner. Academic medical center. Donor semen samples from 24 men in 144 aliquots. None. Accuracy, precision, and agreement assessed between the YO device and the SQA-Vision for MSC results. The YO device demonstrated good correlation and good to moderate agreement with the SQA-Vision for MSC results up to a range of 94 × 106/mL with Pearson and concordance correlation coefficient above 0.92. The YO also showed a very high level of accuracy (97.8%) with positive and negative percent agreement above 94%. The difference in coefficient of variation between the YO and the SQA-Vision was low (between 9.4% and 11.2%) and not statistically significant. The precision among the YO phone devices was lower (16.0%) than the manufacturer's claim of ≤20%. The smartphone-based device has a high level of accuracy and precision when compared with the SQA-Vision. It can detect samples with abnormally "low" MSC (below 6 × 106/mL cutoff), which supports its use as an effective home sperm test for screening "low" and "moderate/normal" MSC cases. In addition, the device effectively identifies varying levels of normal MSC in a precise manner over a wide range of normal MSC. Thus, the YO Score can improve patient satisfaction and empowerment.

Lateral flow aptamer assay integrated smartphone-based portable device for simultaneous detection of multiple targets using upconversion nanoparticles

Simultaneous detection of multiple targets with different analyte-recognition reactions in the same sample in a rapid, low-cost and reliable way has immense potential with widespread applications in food safety, medical diagnostics and environmental monitoring. Herein, we developed a lateral flow aptamer assay (LFAA) integrated smartphone-based portable device for highly sensitive and precise detection of multiple targets, using aptamers functionalized multi-colored upconversion nanoparticles as probes. The developed LFAA can provide rapid and sensitive analysis of three different kinds of targets (i.e., small molecules, ions and bacteria) without significant cross-reaction by using separate color channels. By using the competitive format, the concentration of each target can be determined from the color intensity of the corresponding colored band. With the LFAA, we have achieved detection ranges of 10–104 ppb, 0.01–50 μg/mL and 150–2000 CFU/mL and detection limits of 5 ppb, 3 ng/mL and 85 CFU/mL for mercury ions, ochratoxin A and Salmonella (as template analytes), respectively. The LFAA was further used for detection in real water samples (i.e., tap water) within 30 min. Subsequently, a smartphone-based device was used instead of a CCD camera to read the results, which could make the detection process rapid and portable. Therefore, the developed LFAA holds great potential as a sensitive, specific, convenient and stable platform for point-of-care detection of multiple targets in various fields.

A Nanozyme- and Ambient Light-Based Smartphone Platform for Simultaneous Detection of Dual Biomarkers from Exposure to Organophosphorus Pesticides.

A transparent, lateral-flow test strip coupled with a smartphone-based ambient light sensor was first proposed for detecting enzymatic inhibition and phosphorylation. The principle of the platform is based on the simultaneous measurement of the total amount of the enzyme and enzyme activity to biomonitor exposure to organophosphorus (OP) pesticides. In this study, butyrylcholinesterase (BChE) was adopted as the model enzyme and ethyl paraoxon was chosen as an analyte representing OP pesticides. The total amount of BChE was quantified by a sensitive colorimetric signal originating from a sandwich immunochromatographic assay utilizing PtPd nanoparticles as a colorimetric probe, which exhibited excellent catalytic activity for phenols. In the sandwich immunoassay, only one antibody against BChE was simultaneously utilized as the recognition antibody and the labeling antibody due to the tetrameric structure of native BChE. The BChE activity was estimated by another colorimetric signal using the Ellman assay. Both colorimetric signals on two separated test strips were detected by the smartphone-based ambient light sensor. The proposed sensor operated with an LED in a 3D-printed substrate, which emitted excitation light and transmitted it through a transparent, lateral-flow test strip. With the increase in the colorimetric signal in the test line of the test strip, the intensity of the transmitted light decreased. The smartphone-based sensor showed excellent linear responses for assaying the total amount of BChE and active BChE ranging from 0.05 to 6.4 nM and from 0.1 to 6.4 nM, respectively. A high portability and low detection limit were simultaneously realized in the common smartphone-based device. This low-cost, portable, easy-operation, and sensitive immunoassay strategy shows great potential for online detection of OP exposure and monitoring other disease biomarkers.

A smartphone-based point-of-care quantitative urinalysis device for chronic kidney disease patients

This paper presents the design and development of a smartphone-based urinalysis device that has the ability for chronic kidney disease (CKD) patients themselves to conduct rapid and reliable quantitative urinalysis of human serum albumin (HSA) using an aggregation-induced emission (AIE) nanomaterial bioprobe with their own smartphones. The focus of this paper is a novel solution to the device agnosticism issue as a wide diversity of smartphones co-exist in the market. The solution comprises: a) custom-design and fabrication of an imaging housing that provides a consistent imaging condition regardless of the physical dimensions and the camera position of the smartphone used, b) orchestration of an image processing and analysis process that produces consistent image colour intensity values regardless of the camera sensor and imaging software used by the smartphone, and c) special design and development of an intuitive cross-platform mobile application that is scalable to growth, adaptable to changes, resilient to loss of data, and has an extremely low requirement for smartphone hardware. Preliminary evaluation of the device has confirmed the effectiveness of the proposed solution and the viability of such a smartphone-based device for people who have already developed or are prone to CKD to regularly perform point-of-care (POC) urine testing in order to self monitor their own health conditions without the burden of frequent visits to their doctors.

A simple and compact smartphone-based device for the quantitative readout of colloidal gold lateral flow immunoassay strips

Colloidal gold lateral flow immunoassay strips (AuNPs-LFIS) have been widely applied as qualitative diagnostic tools for point-of-care tests (POCT). If strip readers were incorporated, their use could be extended to quantitative analysis. However, their cost and non-portability render commercial strip readers unavailable for use in either home testing, community or rural hospital diagnosis. This is particularly true for on-site testing. Here, a smartphone-based reader was designed and 3D-printed for quantitatively assess AuNPs-LFIS. The basic principle of the devise was relying on a smartphone’s ambient light sensor (SPALS). This sensor was harnessed to measure the transmitted light intensities originating from the T-lines on the strips, the transmitted light intensities vary with concentration of AuNP on the T-lines. To validate this approach, our newly developed smartphone’s ambient light sensor-based reader (SPALS-reader) was used to readout AuNPs-LFIS of three analytical targets: cadmium ion (Cd2+; limit of detection (LOD) was 0.16 ng/mL), clenbuterol (CL; LOD was 0.046 ng/mL), and porcine epidemic diarrhea virus (PEDV; LOD was 0.055 μg/mL). The result showed good consistency with the results of conventional image analysis approaches, indicating that the smartphone-based device is appropriate for use in AuNPs-LFIS readouts. Compared with the traditional analysis method, the developed AuNPs-LFIS reader is easier operated, lower cost and more portable, which provided an on-site quantitative analysis tool for AuNPs-LFIS and enhances the applied range of AuNPs-LFIS.