Highly Specific Detection of Oxytocin in Saliva.

Oxytocin is a peptide neurophysin hormone made up of nine amino acids and is used in induction of one in four births worldwide (more than 13 percent in the United States). Herein, we have developed an antibody alternative aptamer-based electrochemical assay for real-time and point-of-care detection of oxytocin in non-invasive saliva samples. This assay approach is rapid, highly sensitive, specific, and cost-effective. Our aptamer-based electrochemical assay can detect as little as 1 pg/mL of oxytocin in less than 2 min in commercially available pooled saliva samples. Additionally, we did not observe any false positive or false negative signals. This electrochemical assay has the potential to be utilized as a point-of-care monitor for rapid and real-time oxytocin detection in various biological samples such as saliva, blood, and hair extracts.

The effect of a pharmaceutical transitional care program on rehospitalisations in internal medicine patients: an interrupted-time-series study.

BACKGROUND: Medication errors at transition of care can adversely affect patient safety. The objective of this study is to determine the effect of a transitional pharmaceutical care program on unplanned rehospitalisations. METHODS: An interrupted-time-series study was performed, including patients from the Internal Medicine department using at least one prescription drug. The program consisted of medication reconciliation, patient counselling at discharge, and communication to healthcare providers in primary care. The primary outcome was the proportion of patients with an unplanned rehospitalisation within six months post-discharge. Secondary outcomes were drug-related hospital visits, drug-related problems (DRPs), adherence, believes about medication, and patient satisfaction. Interrupted time series analysis was used for the primary outcome and descriptive statistics were performed for the secondary outcomes. RESULTS: In total 706 patients were included. At 6 months, the change in trend for unplanned rehospitalisations between usual care and the program group was non-significant (- 0.2, 95% CI -4.9;4.6). There was no significant difference for drug-related visits although visits due to medication reconciliation problems occurred less often (4 usual care versus 1 intervention). Interventions to prevent DRPs were present for all patients in the intervention group (mean: 10 interventions/patient). No effect was seen on adherence and beliefs about medication. Patients were significantly more satisfied with discharge counselling (68.9% usual care vs 87.1% program). CONCLUSIONS: The transitional pharmaceutical care program showed no effect on unplanned rehospitalisations. This lack of effect is probably because the reason for rehospitalisations are multifactorial while the transitional care program focused on medication. There were less hospital visits due to medication reconciliation problems, but further large scale studies are needed due to the small number of drug-related visits. (Dutch trial register: NTR1519).

SPRi-based adenovirus detection using a surrogate antibody method.

Adenovirus infection, which is a waterborne viral disease, is one of the most prevelant causes of human morbidity in the world. Thus, methods for rapid detection of this infectious virus in the environment are urgently needed for public health protection. In this study, we developed a rapid, real-time, sensitive, and label-free SPRi-based biosensor for rapid, sensitive and highly selective detection of adenoviruses. The sensing protocol consists of mixing the sample containing adenovirus with a predetermined concentration of adenovirus antibody. The mixture was filtered to remove the free antibodies from the sample. A secondary antibody, which was specific to the adenovirus antibody, was immobilized onto the SPRi chip surface covalently and the filtrate was flowed over the sensor surface. When the free adenovirus antibodies bound to the surface-immobilized secondary antibodies, we observed this binding via changes in reflectivity. In this approach, a higher amount of adenoviruses resulted in fewer free adenovirus antibodies and thus smaller reflectivity changes. A dose-response curve was generated, and the linear detection range was determined to be from 10 PFU/mL to 5000 PFU/mL with an R(2) value greater than 0.9. The results also showed that the developed biosensing system had a high specificity towards adenovirus (less than 20% signal change when tested in a sample matrix containing rotavirus and lentivirus).

A portable DNAzyme-based optical biosensor for highly sensitive and selective detection of lead (II) in water sample.

A portable, rapid and cost-effective DNAzyme based sensor for lead ions detection in water samples has been developed using an optical fiber sensor platform. The presence of Pb(2+) cleaves the DNAzymes and releases the fluorescent labeled fragments, which further hybridize with the complementary strands immobilized on the optic fiber sensor surface. Subsequent fluorescent signals of the hybridized fluorescent labeled fragment provides quantitative information on the concentrations of Pb(2+) with a dynamic range from 2-75 nM with a detection limit of 1.03 nM (0.21 ng mL(-1)). The proposed sensor also shows good selectivity against other mono and divalent metal ions and thus holds great potential for the construction of general DNAzyme-based sensing platform for the monitoring of other heavy metal ions. The sensor can be regenerated with a 1% SDS solution (pH 1.9) over 100 times without significant deterioration of the sensor performance. This portable sensor system can be potentially applied for on-site real-time inexpensive and easy-to-use monitoring of Pb(2+) in environmental samples such as wastewater effluents or water bodies.

A portable optic fiber aptasensor for sensitive, specific and rapid detection of bisphenol-A in water samples.

Bisphenol A (BPA) is a known endocrine disruptor and one of the most serious environmental contaminants, often present at low levels in various water sources. Therefore, it is very important and necessary to develop a fast, cost-effective, sensitive, and selective method for on-site detection of BPA. Herein, we developed a portable, evanescent, wave fiber-optic aptasensor for rapid, on-site detection of BPA with high sensitivity and selectivity. In this system, the probe DNA molecule, which is the complementary sequence of a small part of the BPA aptamer, was covalently immobilized onto the optical fiber sensor surface. Using an indirect competitive detection mode, samples containing different concentrations of bisphenol A were premixed with a given concentration of fluorescence-labeled BPA aptamer, which binds to bisphenol A with high specificity. Then, the sample mixture was pumped to the sensor surface, and a higher concentration of BPA led to less fluorescence-labeled BPA aptamer hybridized with surface immobilized probe DNA and thus to a lower fluorescence signal. The developed sensing system exhibits a sensitive response to BPA in the range of 2 nM to 100 nM with a low detection limit of 1.86 nM (0.45 ng ml(-1)) under the optimal conditions. The biosensors showed good reproducibility, stability, and selectivity for BPA detection. Finally, this proposed sensor was successfully employed to determine the presence of BPA in wastewater samples.

Aptamer-based optical biosensor for rapid and sensitive detection of 17ß-estradiol in water samples.

Required routine monitoring of endocrine disrupting compounds (EDCs) in water samples, as posed by EPA Unregulated Contaminant Regulation (UCMR3), demands for cost-effective, reliable and sensitive EDC detection methods. This study reports a reusable evanescent wave aptamer-based biosensor for rapid, sensitive and highly selective detection of 17ß-estradiol, an EDC that is frequently detected in environmental water samples. In this system, the capture molecular, ß-estradiol 6-(O-carboxy-methyl)oxime-BSA, was covalently immobilized onto the optical fiber sensor surface. With an indirect competitive detection mode, samples containing different concentrations of 17ß-estradiol were premixed with a given concentration of fluorescence-labeled DNA aptamer, which highly specifically binds to 17ß-estradiol. Then, the sample mixture is pumped to the sensor surface, and a higher concentration of 17ß-estradiol leads to less fluorescence-labeled DNA aptamer bound to the sensor surface and thus to lower fluorescence signal. The dose-response curve of 17ß-estradiol was established and a detection limit was determined as 2.1 nM (0.6 ng mL(-1)). The high specificity and selectivity of the sensor were demonstrated by evaluating its response to a number of potentially interfering EDCs. Potential interference of real environmental sample matrix was assessed by spiked samples in several tertiary wastewater effluents. The sensor can be regenerated with a 0.5% SDS solution (pH 1.9) over tens of times without significant deterioration of the sensor performance. This portable sensor system can be potentially applied for on-site real-time inexpensive and easy-to-use monitoring of 17ß-estradiol in environmental samples such as effluents or water bodies.