Nucleic acid-functionalized upconversion luminescence biosensor based on strand displacement-mediated signal amplification for the detection of trivalent chromium ions.

Background: Rapid industrial development has generated serious pollution, including the presence of toxic and harmful heavy metal ions. Among them, trivalent chromium ion (Cr) is a very important element that poses a threat to life and health in our industrial wastewater pollution. Thus, it is important to develop efficient fluorescence methods for Cr detection.

A cavity induced mode hybridization plasmonic sensor for portable detection of exosomes.

Exosomes have been considered as promising biomarkers for cancer diagnosis due to their abundant information from originating cells. However, sensitive and reliable detection of exosomes is still facing technically challenges due to the lack of a sensing platform with high sensitivity and reproducibility. To address the challenges, here we propose a portable surface plasmon resonance (SPR) sensing of exosomes with a three-layer Au mirror/SiO spacer/Au nanohole sensor, fabricated by an economical polystyrene nanosphere self-assembly method.

Unlabelled LRET biosensor based on double-stranded DNA for the detection of anthraquinone anticancer drugs.

Based on upconversion nanoparticles (UCNPs) as energy donor and herring sperm DNA (hsDNA) as molecular recognition element, an unlabelled upconversion luminescence (UCL) affinity biosensor was constructed for the detection of anthraquinone (AQ) anticancer drugs in biological fluids. AQ anticancer drugs can insert into the double helix structure of hsDNA on the surface of UCNPs, thereby shortening the distance from UCNPs. Therefore, the luminescence resonance energy transfer (LRET) phenomenon is effectively triggered between UCNPs and AQ anticancer drugs.

Upconversion luminescence nanosensor for detection of Fe and phosphate ion based on the inner-filter effect.

In this work, an upconversion luminescence (UCL) nanosensor for fast detection of ferric ion (Fe) and phosphate ion (Pi) is developed based on the inner-filter effect (IFE) between NaYF:Yb/Er upconversion nanoparticles (UCNPs) and Fe-hypocrellin B (HB) complex. Fe-HB complex has strong absorption band (450-650 nm), which overlaps with the green emission peak of UCNPs at 545 nm. By adding Fe and Pi, the UCNPs-HB system produces the red-shift change of absorption spectrum, which leads to the "on-off-on" process of IFE.

Paper-based LRET sensor for the detection of total heavy rare-earth ions.

Based on the mechanism of luminescence resonance energy transfer (LRET) and using a special single strand DNA as the recognition element, a portable paper-based sensor for the accurate detection of total heavy rare-earth ions (mainly Gd, Tb and Dy) concentration was proposed. The RNA cleaving-DNAzyme should recognize rare-earth ions to cleave RNA on DNA duplexes linking UCNPs and AuNPs, causing UCNPs and AuNPs to approach each other, inducing LRET, which attenuated the green upconversion luminescence (UCL) triggered by the 980 nm laser. UCL was captured by a charge-coupled device (CCD) image sensor and processed with the red-green-blue (RGB) image to quantitatively analyze heavy rare-earth ions in the samples.

Codelivery of π-π Stacked Dual Anticancer Drugs Based on Aloe-Derived Nanovesicles for Breast Cancer Therapy.

To overcome the low efficacy of conventional monotherapeutic approaches that use a single drug, functional nanocarriers loaded with an amalgamation of anticancer drugs have been promising in cancer therapy. Herein, aloe-derived nanovesicles (gADNVs) are modified with an active integrin-targeted peptide (Arg-Gly-Asp, RGD) by the postinsertion technique to deliver indocyanine green (ICG) and doxorubicin (DOX) for efficient breast cancer therapy. We presented for the first time that the π-π stacking interaction can turn the "competitive" relationship of ICG and DOX inside gADNVs into a "cooperative" relationship and enhance their loading efficiency.

Sensitive fluorescent detection of exosomal microRNA based on enzymes-assisted dual-signal amplification.

The analysis of microRNAs (miRNAs) in exosomes offers significant information for a rapid and non-invasive diagnosis of cancer. However, the clinical utility of miRNAs as biomarkers is often hampered by their low abundance in exosomes. Herein, we develop a dual-signal amplification biosensor for the sensitive detection of exosomal miRNA-21 (miR-21).

Upconversion luminescence-based aptasensor for the detection of thyroid-stimulating hormone in serum.

Thyroid-stimulating hormone (TSH) plays a crucial physiological and pathological role in humans, and a timely and sensitive detection of TSH is critical for early diagnosis and prevention of thyroid-related diseases. Herein, we developed a simple wash-free biological aptasensor based on luminescence resonance energy transfer (LRET) between NaYF:Yb,Er upconversion nanoparticles (UCNPs) and tetramethylrhodamine (TAMRA) for the detection of TSH with high sensitivity. In this LRET system, UCNPs as donors and TAMRA as receptors were modified with nucleic acid aptamers Apt-1 and Apt-2, respectively.

Sensitive, Highly Stable, and Anti-Fouling Electrode with Hexanethiol and Poly-A Modification for Exosomal microRNA Detection.

It remains a huge challenge to integrate the sensitivity, stability, reproducibility, and anti-fouling ability of electrochemical biosensors for practical applications. Herein, we propose a self-assembled electrode combining hexanethiol (HT), poly-adenine (poly-A), and cholesteryl-modified DNA to meet this challenge. HT can tightly pack at the electrode interface to form a hydrophobic self-assembled monolayer (SAM), effectively improving the stability and signal-to-noise ratio (SNR) of electrochemical detection.

A dual-modal aptasensor based on a multifunctional acridone derivate for exosomes detection.

Exosomes are promising biomarkers for cancer screening, but the development of a robust approach that can sensitively and accurately detect exosomes remains challenging. In the present study, an aptasensor based on the multifunctional signal probe 10-benzyl-2-amino-acridone (BAA) was developed for the colorimetric and photoelectrochemical detection and quantitation of exosomes. Exosomes are captured by cholesterol DNA anchor-modified magnetic beads (MBs) through hydrophobic interactions.

Aloe derived nanovesicle as a functional carrier for indocyanine green encapsulation and phototherapy.

Background: Cancer is one of the devastating diseases in the world. The development of nanocarrier provides a promising perspective for improving cancer therapeutic efficacy. However, the issues with potential toxicity, quantity production, and excessive costs limit their further applications in clinical practice.

Detection of phospholipase A in serum based on LRET mechanism between upconversion nanoparticles and SYBR green I.

Phospholipase A (PLA) may be a vital biomarker for the prediction and diagnosis of some diseases. Consequently, it is of great significance to quantitatively detect PLA in biologic samples. Herein, on the basis of the principle of luminescence resonance energy transfer (LRET) between upconversion nanoparticles (UCNPs) and SYBR Green I (SG), we proposed a technology for the highly sensitive detection of PLA amount.

Colorimetric detection of exosomal microRNA through switching the visible-light-induced oxidase mimic activity of acridone derivate.

Exosomal microRNAs (miRNAs) are vital biomarkers for early diagnosis and prognosis monitoring of cancer. Yet, convenient and controllable detection of exosomal miRNA still remains challenges because of lacking of adequately simple and robust assay platforms. In this paper, it is first time to study the visible-light-induced oxidase mimic activity of 10-methyl-2-amino-acridone (MAA) being able to be switched by Cu and DNA.

A nature-inspired colorimetric and fluorescent dual-modal biosensor for exosomes detection.

As non-invasive biomarkers, exosomes are of great significance to diseases diagnosis. However, sensitive and accurate detection of exosomes still remains technical challenges. Herein, inspired by nature's "one-to-many" concept, we design a biosensor mimicking the cactus with numerous thorns to detect exosomes.

A DNA electrochemical biosensor based on triplex DNA-templated Ag/Pt nanoclusters for the detection of single-nucleotide variant.

A label-free electrochemical biosensor based on the triplex DNA-templated Ag/Pt bimetallic nanoclusters (triplex-Ag/PtNCs) and locked nucleic acid (LNA) modified X-shaped DNA probe was developed for the detection of single-nucleotide variant (SNV) related to β-thalassemia. Firstly, using triplex DNA as template, a site-specific and homogeneous Ag/PtNCs was prepared, which can effectively catalyze the 3,3,5,5-tetramethylbenzidine-HO system and thus be employed as a signal reporter in the field of electrochemical biosensor. Secondly, the LNA modified X-shaped probes were assembled on gold electrode surface, which can only be dissociated in the presence of target, leading to the hybridization with triplex-Ag/PtNCs and significant increase of current signal.

Acridone Derivate Simultaneously Featuring Multiple Functions and Its Applications.

Compared with plenty of single-functional molecules, multifunctional molecules are scarce and have high demand in further research. In this work, a multifunctional molecule called 10-methyl-2-amino-acridone (MAA) is presented. Interestingly, MAA simultaneously features electrochemistry, two-photon fluorescence, visible-light-induced oxidase mimic, and photoelectrochemistry (PEC) activity, and the related properties are studied in detailed.

A Ratiometric Fluorescent Bioprobe Based on Carbon Dots and Acridone Derivate for Signal Amplification Detection Exosomal microRNA.

Recently, sensitive and selective detection of exosomal microRNAs (miRNAs) has been garnering significant attention, because it is related to many complex diseases, including cancer. Herein, we report a ratiometric fluorescent bioprobe based on DNA-labeled carbon dots (DNA-CDs) and 5,7-dinitro-2-sulfo-acridone (DSA) coupling with the target-catalyzing signal amplification for the detection of exosomal miRNA-21. There was high fluorescence resonance energy transfer (FRET) efficiency between carbon dots (CDs) and DSA when the bioprobe was assembled.

A paper-supported aptasensor based on upconversion luminescence resonance energy transfer for the accessible determination of exosomes.

Exosomes, as potential cancer diagnostic markers have received close attention in recent years. However, there is still a lack of simple and convenient methods to detect and quantitate exosomes. Herein, we used a simple paper-supported aptasensor based on luminescence resonance energy transfer (LRET) from upconversion nanoparticles (UCNPs) to gold nanorods (Au NRs) for the accessible determination of exosomes.

Can Coinage Metal Atoms Be Capable of Serving as an Excess Electron Source of Alkalides with Considerable Nonlinear Optical Responses?

Alkalides, as a representative kind of excess electron compounds, have been demonstrated to be potential nonlinear optical (NLO) materials with large static first hyperpolarizabilities (β). The possibility of utilizing coinage metal atoms as a novel excess electron source to design a series of alkalides, i.e.

A visible and colorimetric aptasensor based on DNA-capped single-walled carbon nanotubes for detection of exosomes.

Recently, many studies have shown the potential use of circulating exosomes as novel biomarkers for monitoring and predicting a number of complex diseases, including cancer. However, reliable and cost-effective detection of exosomes in routine clinical settings, still remain a difficult task, mainly due to the lack of adequately easy and fast assay platforms. Therefore, we demonstrate here the development of a visible and simple method for the detection of exosomes by integrating single-walled carbon nanotubes that being excellent water solubility (s-SWCNTs) and aptamer.

A upconversion luminescene biosensor based on dual-signal amplification for the detection of short DNA species of c-erbB-2 oncogene.

High-sensitivity detection of trace amounts of c-erbB-2 oncogene was reported to be equal to or surpass the ability of CA 15-3 for early diagnosis and/or follow-up recurrent screening of breast cancer. Therefore, in the current study, by using upconversion nanoparticles (UCNPs), rare earth-doped NaYF4:Yb(3+)/Er(3+) as the luminescent labels, a upconversion luminescent (UCL) biosensor based on dual-signal amplification of exonuclease III (ExoIII)-assisted target cycles and long-range self-assembly DNA concatamers was developed for the detection of c-erbB-2 oncogene. The proposed biosensor exhibited ultrasensitive detection with limit as low as 40 aM, which may express the potential of being used in trace analysis of c-erbB-2 oncogene and early diagnosis of breast cancer.

Colorimetric determination of sarcosine in urine samples of prostatic carcinoma by mimic enzyme palladium nanoparticles.

The proposed palladium nanoparticles (Pd NPs), which with the catalytic activity similar to the horseradish peroxidase (HRP) mimic enzyme, can effectively catalyze the H2O2-mediated oxidation of 3,3',5,5'-tetramethylbenzidine sulfate (TMB) accompanied with a color change from colorless to blue in solution. And as a result, the sensitive detection of sarcosine can be realized by the naked eye observation and ultraviolet spectrophotometry, using Pd NPs as catalyst and TMB as the substrate of the simulation enzyme catalytic reaction. Under the optimal condition, the catalytic system of Pd NPs mimic enzyme can be used for the detection of sarcosine.