Wireless, noninvasive therapeutic drug monitoring system for saliva measurement toward medication management of schizophrenia.

As an efficient patient management tool of precision medicine, decentralized therapeutic drug monitoring (TDM) provides new vision for therapy adherence and health management of schizophrenia in a convenient manner. To dispense with psychologically burdensome blood sampling and to achieve real-time, noninvasive, and continual circulating tracking of drugs with narrow therapeutic window, we study the temporal metabolism of clozapine, an antipsychotic with severe side effect, in rat saliva by a wireless, integrated and patient-friendly smart lollipop sensing system. Highly sensitive and efficient sensing performance with acceptable anti-biofouling property was realized based on the synergistic effect of electrodeposited reduced graphene oxide and ionic liquids in pretreatment-free saliva with low detection limit and good accuracy cross-validated with conventional method. On this basis, continual salivary drug levels with distinctive pharmacokinetics were found in different routes of drug administration. Pilot experiment reveals a strong correlation between blood and saliva clozapine and a positive relationship between drug dosage and salivary drug level, indicating potential applications presented by noninvasive saliva analysis towards patient-centered and personalized pharmacotherapy and adherence management via proposed smart lollipop system.

Smartphone-Based Electrochemical Systems for Glucose Monitoring in Biofluids: A Review.

As a vital biomarker, glucose plays an important role in multiple physiological and pathological processes. Thus, glucose detection has become an important direction in the electrochemical analysis field. In order to realize more convenient, real-time, comfortable and accurate monitoring, smartphone-based portable, wearable and implantable electrochemical glucose monitoring is progressing rapidly. In this review, we firstly introduce technologies integrated in smartphones and the advantages of these technologies in electrochemical glucose detection. Subsequently, this overview illustrates the advances of smartphone-based portable, wearable and implantable electrochemical glucose monitoring systems in diverse biofluids over the last ten years (2012-2022). Specifically, some interesting and innovative technologies are highlighted. In the last section, after discussing the challenges in this field, we offer some future directions, such as application of advanced nanomaterials, novel power sources, simultaneous detection of multiple markers and a closed-loop system.

Elimination of oxygen interference in the photoelectrochemical sensor with ferricyanide shield oxygen reduction for point of care testing.

As a sensitive and promising detection method, photoelectrochemical (PEC) sensor has been widely used in biochemical analysis field. However, the interferences from environment, especially dissolved oxygen, often impact the stability and precision of PEC sensors, which limit its practical applications. Here, we report a dissolved oxygen insensitive PEC sensor based on a proposed indirect electron transfer model. Through the detailed study of the charge transfer process, we determined that the photocurrent mainly comes from the electrochemical reaction between the photochemical products and the electrode, rather than direct charge transfer between the photoelectric materials and the electrode. The newly designed PEC sensor used ferricyanide to shield oxygen reduction and eliminated the influence from variable oxygen solubility. This sensor maintained robust responses over an extremely wide range (1.0-7.5 mg/L) of dissolved oxygen concentrations. To further demonstrate its capability, a smartphone based portable immunosensor was constructed for the detection of human serum albumin (HSA), which exhibited excellent stability and accuracy. The relative error of current was reduced by 81.3% over traditional electron donor solution. This work effectively improves the stability of PEC sensors, and lays the foundation for the subsequently practical applications of PEC sensor in point-of-care testing.

Biosensor based on polyaniline-polyacrylonitrile-graphene hybrid assemblies for the determination of phenolic compounds in water samples.

Phenolic compounds are major environmental pollutants due to their toxic and hazardous nature on human health. A fast, sensitive and stable sensor for determination of phenolic compounds in the environmental water remains challenging. Herein, a biosensor platform with stable response current was fabricated by entrapment of polyphenol oxidase (PPO) into hybrid assemblies of the conducting polyaniline (PAni)-porous polyacrylonitrile (Pan)-nanostructured graphene (GRA) and phase inversion process. The porous structure of Pan provided a favorable microenvironment for easily binding to PAni and GRA to obtain hybrid assemblies for effective immobilization of enzyme and increased synergistic effect. The morphologies and the electrochemical behaviors of the as-prepared biosensor were investigated using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. The proposed biosensor showed excellent sensitivity (6.46 µA µM-1 cm-2) and fast response time (˜5 s) with low detection limit (2.65×10-7 M) under the optimal pH value and applied potential. The biosensor was highly selective towards p-cresol that almost no signal was detected from common interferents. The biosensor was used for determination of phenolic compounds in water samples with satisfactory results compared with that of UPLC, demonstrating its great potential as a biosensor for the rapid determination of phenolic pollutants.