Zero-Biased Photoelectrochemical Detection of Cardiac Biomarker Myoglobin Based on CdSeS/ZnS Quantum Dots and Barium Titanate Perovskite.

Cardiovascular diseases are considered one of the leading causes of premature mortality of patients worldwide. Therefore, rapid diagnosis of these diseases is crucial to ensure the patient's survival. During a heart attack or severe muscle damage, myoglobin is rapidly released in the body to constitute itself as a precise biomarker of acute myocardial infarction. Thus, we described the photoelectrochemical immunosensor development to detect myoglobin. It was based on fluorine-doped tin oxide modified with CdSeS/ZnSe quantum dots and barium titanate (BTO), designated as CdSeS/ZnSQDS/BTO. It was characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and amperometry. The anodic photocurrent at the potential of 0 V (vs. Ag/AgCl) and pH 7.4 was found linearly related to the myoglobin (Mb) concentration from 0.01 to 1000 ng mL-1. Furthermore, the immunosensor showed an average recovery rate of 95.7-110.7% for the determination of myoglobin.

Cadmium selenide sulfide quantum dots with tuneable emission profiles: An electrochemiluminescence platform for the determination of TIMP-1 protein.

The development of electrochemiluminescent (ECL) luminophores with tuneable emission profiles is a key requirement in the development of multi-analyte ECL sensing platforms. This study presents the first reported use of cadmium selenide sulfide (CdSeS) quantum dots (QDs) as ECL emitters in which both the ECL emission profile and cathodic potential can be tailored by alteration of the Se/S ratio. CdSeS QDs were synthesised using an aqueous synthetic route thereby avoiding the use of organic reagents, high temperatures and inert gasses. The suitability of the CdSeS QDs to ECL sensing applications is demonstrated via the quantitative determination of TIMP-1 protein at clinically relevant concentrations. The developed cathodic ECL immunosensor exhibited a detectable linear range of 6-60 ng/mL and a limit of detection (LOD) of 1.54 ng/mL. TIMP-1 protein plays a crucial role in pregnancy, wound healing, and cancer prognosis.

Se/S Ratio-Dependent Properties and Application of Gradient-Alloyed CdSe1- xS x Quantum Dots: Shell-free Structure, Non-blinking Photoluminescence with Single-Exponential Decay, and Efficient QLEDs.

Colloidal quantum dots (QDs) are promising optical and optoelectronic materials for various applications. The excited state properties are important indexes to assess the quality of QDs and may directly affect their applications. Different from controlling surface engineering (surface ligands, shell thickness, etc.) to adjust excited state properties, high-quality shell-free alloyed CdSe1- xS x (simplified as CdSeS) QDs with controlled excited state properties were synthesized by tuning the composition and using diphenylphosphine as a beneficial additive at a low temperature (∼180 °C). The optimized CdSeS shell-free alloyed QDs (Se/S = 1:8) exhibited excellent optical properties with tuning of the excited state, including single-exponential photoluminescence (PL) decay dynamics, a narrow full width at half maximum of 28 nm, and non-blinking emission behavior (>98% "on" time). Furthermore, all-solution-processed, multilayered quantum dot light-emitting diodes were fabricated using the conventional device structure to assess the performance of QDs with composition-controlled excited states. The best device displayed a maximum luminance of 92,330 cd m-2, a current efficiency of 50.3 cd A-1, and an external quantum efficiency of 14.5%.

CdSeS Nanowires: Compositionally Controlled Band Gap and Exciton Dynamics.

CdS, CdSe, and ternary CdSexS(1-x) are some of the most widely studied II-VI semiconductors due to their broad range of applications and promising performance in numerous systems. One-dimensional semiconductor nanowires offer the ability to conduct charges efficiently along the length of the wire, which has potential charge transport benefits compared to nanoparticles. Herein, we report a simple, inexpensive synthetic procedure for high quality CdSeS nanowires where the composition can be easily modulated from pure CdSe to pure CdS by simply adjusting the Se:S precursor ratio. This allows for tuning of the absorption and emission properties of the nanowires across the visible spectrum. The CdSeS nanowires have a wurtzite crystal structure and grow along the [001] direction. As measured by femtosecond transient absorption spectroscopy, the short component of the excited state lifetime remains relatively constant at ∼10 ps with increasing Se; however, the contribution of this short lifetime component increased dramatically from 8.4% to 57.7% with increasing Se content. These CdSeS nanowires offer facile synthesis and widely adjustable optical properties, characteristics that give them broad potential applications in the fields of optoelectronics, and photovoltaics.