Spicy Recipe for At-Home Diagnostics: Smart Salivary Sensors for Point-of-Care Diagnosis of Jaundice.

Even though significant advances have been made, there is still a lack of reliable sensors capable of noninvasively monitoring bilirubin and diagnosing jaundice as the most common neonatal disease, particularly at the point-of-care (POC) where blood sampling from infants is accompanied by serious challenges and concerns. Herein, for the first time, using an easy-to-fabricate/use assay, we demonstrate the capability of curcumin embedded within paper for noninvasive optical monitoring of bilirubin in saliva. The highly selective sensing of the developed sensor toward bilirubin is attributed to bilirubin photoisomerization under blue light exposure, which can selectively restore the bilirubin-induced quenched fluorescence of curcumin. We also fabricated an IoT-enabled hand-held optoelectronic reader to measure and quantify the fluorescence and color signals of our sensor. Clinical analysis on the saliva of 18 jaundiced infants by using our developed smart salivary sensor proved that it is amenable to be widely exploited in POC applications for bilirubin monitoring as there are good correlations between its results with those of reference methods in saliva and blood. Meeting all WHO's REASSURED criteria by our developed sensor makes it a highly promising sensor for smart noninvasive diagnosis and therapeutic monitoring of jaundice, hepatitis, and other bilirubin-induced neurologic diseases at the POC.

Smart Wearable Nanopaper Patch for Continuous Multiplexed Optical Monitoring of Sweat Parameters.

Notwithstanding the substantial progress in optical wearable sensing devices, developing wearable optical sensors for simultaneous, real-time, and continuous monitoring of multiple biomarkers is still an important, yet unmet, demand. Aiming to address this need, we introduced for the first time a smart wearable optical sensor (SWOS) platform combining a multiplexed sweat sensor sticker with its IoT-enabled readout module. We employed our SWOS system for on-body continuous, real-time, and simultaneous fluorimetric monitoring of sweat volume (physical parameter) and pH (chemical marker). Herein, a variation in moisture (5-45 µL) or pH (4.0-7.0) causes a color/fluorescence change in the copper chloride/fluorescein immobilized within a transparent chitin nanopaper (ChNP) in a selective and reversible manner. Human experiments conducted on athletic volunteers during exercise confirm that our developed SWOS platform can be efficiently exploited for smart perspiration analysis toward personalized health monitoring. Moreover, our system can be further extended for the continuous and real-time multiplexed monitoring of various biomarkers (metabolites, proteins, or drugs) of sweat or other biofluids (for example, analyzing exhaled breath by integrating onto a facemask).

Easy Diagnosis of Jaundice: A Smartphone-Based Nanosensor Bioplatform Using Photoluminescent Bacterial Nanopaper for Point-of-Care Diagnosis of Hyperbilirubinemia.

One of the concerns of parents in the first days of their baby's birth is the baby's risk of jaundice/hyperbilirubinemia. This is because more than 60% of babies are born with jaundice that, if not timely diagnosed and subsequently treated, can lead to serious damage to their health. On the other hand, despite recent progress in sensor technology for clinical applications, the development of easy-to-use, cost-effective, sensitive, specific, and portable diagnostic devices, which use nontoxic and biodegradable materials in their design and fabrication, is still in high demand. Herein we present an easy-to-use, cost-effective, selective, nontoxic, and disposable photoluminescent nanopaper-based assay kit with a smartphone readout for easy diagnosis of neonatal jaundice through visual determination of Bilirubin (BR) in infants' blood samples. The developed BR assay kit comprises highly photoluminescent carbon dot (CD) sensing probes embedded in a bacterial cellulose (BC) nanopaper substrate (CDBN). The photoluminescence (PL) of the developed BR sensor is quenched in the presence of BR as a PL quencher and then selectively recovered upon blue light (λ = 470 nm) exposure, due to conversion of the unconjugated BR to the colorless oxidation products (non-PL quencher) through BR photoisomerization and photooxidation, that subsequently leads to selective PL enhancement of CDBN. The recovered PL intensity of the developed BR assay kit, which was monitored by integrated smartphone camera, was linearly proportional to the concentration of BR in the range of 2-20 mg dL-1. The feasibility of real application of the fabricated smartphone-based BR assay kit was also confirmed via comparing the results of our method with a clinical reference method for determination of BR concentration in infant's blood samples. With the advantages of nontoxicity and the extraordinary physicochemical properties of photoluminescent BC nanopaper as the sensing substrate, along with those of smartphone technology, we believe that our developed smartphone-based BR assay kit, as an easy-to-use, cost-effective (∼0.01 Euro per test), portable and novel sensing bioplatform, can be potentially exploited for sensitive, specific, rapid, and easy BR detection and jaundice diagnosis at the point of care (POC) and in routine clinical laboratories as well.

A study of the interaction tyrosine and DNA using voltammetry and spectroscopy methods.

The interaction of tyrosine (Tyr) with double stranded DNA was studied by cyclic voltammetry, fluorescence emission spectroscopy, and UV-vis spectroscopy. The presence of DNA on a single-walled carbon nanotubes (DNA/SWCNT/GCE) and multi-walled carbon nanotubes (DNA/MWCNT/GCE) modified glassy carbon electrode showed a decrease in the current and a positive shift in the Tyr oxidation peak, indicating the intercalative interaction. The transfer coefficient (α), heterogeneous rate constant (k(s)), and surface concentration (Γ) were calculated in the absence and presence of DNA. The corresponding binding constant of Tyr with DNA and Hill coefficient were obtained from cooperative Hill model. The UV spectroscopic data confirmed the interaction between Tyr and DNA is intercalative with the binding constant of 3.98×10(3) mol(-1) L. Furthermore, the mechanism of fluorescence quenching has been discussed and the binding constant and numbers of binding sites were obtained as 3.37×10(3) mol(-1) L and 2, respectively from the Stern-Volmer plot.