Urinary gonadotropin measurements by enhanced luminometric assays (LIA) for the evaluation of pubertal development

Objectives Determination of LH in urine has proved to be a reliable method for evaluation of pubertal development. The human LH assay based on time-resolved immunofluorometric (IFMA) technology (AutoDELFIA, PerkinElmer, Wallac) has been found to be suitable for this purpose thanks to its high sensitivity but other assays have not been evaluated. We have analyzed our data obtained by another potentially sensitive detection technique, enhanced luminometric assay (LIA) with the objective of finding a viable alternative to IFMA since these may not be available in the future. Methods LIA was used to measure LH and FSH in serum and urine samples from 100 healthy subjects of each Tanner stage and both genders, whose pubertal development has been determined. Results Urinary gonodotropin concentrations measured by LIA correlated well with Tanner stage [(r=0.93 for girls, r=0.81 for boys; p<0.01 for LH) and (r=0.81 for girls, r=0.73 for boys; p<0.01 for FSH)]. LIA determinations revealed the increase in U-LH concentrations during the transition from Tanner stage 1–2 in both girls and boys (p<0.001), whereas U-FSH and S-LH were able to detect the increase from Tanner stage 1–2 only in boys or girls, respectively (both p<0.001). Conclusions Measurement of urinary gonadotropin concentrations by LIA may be useful for the evaluation of overall pubertal development and also in the detection of transition from prepuberty to puberty.

Biocompatible nanomicelles for sensitive detection and photodynamic therapy of early-stage cancer

The lack of sensitive detection technique and agents for early-stage tumors, which are characterized with small size, juvenile blood vessel and scarce secreted markers, has hampered the timely cancer therapy...

Fluorescence immunosensor for cardiac troponin T based on Förster resonance energy transfer (FRET) between carbon dot and MoS2 nano-couple

The study demonstrates a sensitive detection technique for cardiac troponin T (cTnT) using FRET based carbon dot (CD) and molybdenum disulfide (MoS2) nano-couple.

Enzymatically enhanced collisions on ultramicroelectrodes for specific and rapid detection of individual viruses

We report the specific collision of a single murine cytomegalovirus (MCMV) on a platinum ultramicroelectrode (UME, radius of 1 μm). Antibody directed against the viral surface protein glycoprotein B functionalized with glucose oxidase (GOx) allowed for specific detection of the virus in solution and a biological sample (urine). The oxidation of ferrocene methanol to ferrocenium methanol was carried out at the electrode surface, and the ferrocenium methanol acted as the cosubstrate to GOx to catalyze the oxidation of glucose to gluconolactone. In the presence of glucose, the incident collision of a GOx-covered virus onto the UME while ferrocene methanol was being oxidized produced stepwise increases in current as observed by amperometry. These current increases were observed due to the feedback loop of ferrocene methanol to the surface of the electrode after GOx reduces ferrocenium methanol back to ferrocene. Negative controls (i) without glucose, (ii) with an irrelevant virus (murine gammaherpesvirus 68), and (iii) without either virus do not display these current increases. Stepwise current decreases were observed for the prior two negative controls and no discrete events were observed for the latter. We further apply this method to the detection of MCMV in urine of infected mice. The method provides for a selective, rapid, and sensitive detection technique based on electrochemical collisions.

The Application of Phase-Sensitive Detection Technology in the Lateral Logging

In the course of logging, the instrument needs to measure the formation parameters, at the same time we need to solve the problem that the various signals with different frequencies will be produced. The technology with the use of phase sensitive detection filter can reduce mutual interference between the various signals, which can achieve the purpose of improving the measurement accuracy. This paper analyzed the work principal of phase sensitive detection technique in lateral logging applications, the data shows that this method can effectively eliminate or reduce the impact phase, thereby improving the measurement accuracy of lateral logging instrument.

A novel detection technique of polyamide binding sites by photo-induced electron transfer in BrU substituted DNA

We demonstrate a highly sensitive detection technique of polyamide binding sites using the photochemistry of BrU labeled DNA.

Rare Earth Doped Apatite Nanomaterials for Biological Application

In most biological analyses, a sensitive detection technique is primarily dependent on the fluorescence labeling agent. New generation of fluorophores called rare earth doped apatite nanoparticle (REAnp) has the ability to emit near infrared radiations which are of low absorptivity by tissue chromophores and especially suitable for biological system imaging. Moreover, bioapatite is demonstrated to be an excellent candidate for biomedical applications because of its biocompatibility, biodegradability, and bioactivity. During recent years a lot of efforts have been made for achievement of REAnp for medical diagnostics and targeted therapeutics applications. In this review, we discuss the significance of REAnps in biological systems, different root of synthesis, and biological applications. Also we discuss the future studies for the effective biological applications of REAnps.