Sensitive detection of cancer biomarker microRNAs （miRNAs） is of vital importance for cancer diagnosis and treatment. Nonetheless, the detection sensitivity in the existing miRNA bioassays is severely limited by the...Sensitive detection of cancer biomarker microRNAs （miRNAs） is of vital importance for cancer diagnosis and treatment. Nonetheless, the detection sensitivity in the existing miRNA bioassays is severely limited by the structural characteristics of miRNA （including small length and high sequence homology） because most of these methods are based on target amplification. Herein, we report a novel approach to sensitive and specific detection of low-abundance miRNA via a unique strategy of nanoprobe dissolution-enhanced fluorescence amplification, in which a capture probe featuring molecular beacon structure is designed. By means of this strategy, miRNA-21 was detected in a linear range from 10 fM to 100 pM with a detection limit as low as 1.38 fM. High selectivity of the newly developed biosensor was demonstrated by the good discrimination against a target with a single-base mismatch. Furthermore, this assay was used for the detection of miRNA-21 added into fetal bovine serum samples with the recovery in the range of 90.2%--108% and coefficients of variation below 10.1%, indicating its promising applications to RNA immunoassays and early cancer diagnosis.展开更多
The accurate detection of blood glucose is of critical importance in the diagnosis and management of diabetes and its complications. Herein, we report a novel strategy based on an upconversion nanoparticles-polydopami...The accurate detection of blood glucose is of critical importance in the diagnosis and management of diabetes and its complications. Herein, we report a novel strategy based on an upconversion nanoparticles-polydopamine （UCNPs-PDA） nanosystem for the accurate detection of glucose in human serum and whole blood through a simple blending of test samples with ligand-free UCNPs, dopamine, and glucose oxidase （GOx）. Owing to the high affinity of lanthanide ions exposed on the surface of ligand-free UCNPs, dopamine monomers could spontaneously attach to the UCNPs and further polymerize to form a PDA shell resulting in a remarkable upconversion luminescence （UCL） quenching （97.4%） of UCNPs under 980-nm excitation. Such UCL quenching can be effectively inhibited by H2O2 produced from the GOx/glucose enzymatic reaction, thus enabling the detection of H2O2 or glucose based on the UCL quenching/inhibition bioassay. Owing to the highly sensitive UCL response and background-free interference of the UCNPs-PDA nanosystem, we achieved a sensitive, selective, and high-throughput bioassay for glucose in human serum and whole blood, thereby revealing the great potential of the UCNPs-PDA nanosystem for the accurate detection of blood glucose or other HRO2-generated biomolecules in clinical bioassays.展开更多
文摘Sensitive detection of cancer biomarker microRNAs （miRNAs） is of vital importance for cancer diagnosis and treatment. Nonetheless, the detection sensitivity in the existing miRNA bioassays is severely limited by the structural characteristics of miRNA （including small length and high sequence homology） because most of these methods are based on target amplification. Herein, we report a novel approach to sensitive and specific detection of low-abundance miRNA via a unique strategy of nanoprobe dissolution-enhanced fluorescence amplification, in which a capture probe featuring molecular beacon structure is designed. By means of this strategy, miRNA-21 was detected in a linear range from 10 fM to 100 pM with a detection limit as low as 1.38 fM. High selectivity of the newly developed biosensor was demonstrated by the good discrimination against a target with a single-base mismatch. Furthermore, this assay was used for the detection of miRNA-21 added into fetal bovine serum samples with the recovery in the range of 90.2%--108% and coefficients of variation below 10.1%, indicating its promising applications to RNA immunoassays and early cancer diagnosis.
文摘The accurate detection of blood glucose is of critical importance in the diagnosis and management of diabetes and its complications. Herein, we report a novel strategy based on an upconversion nanoparticles-polydopamine （UCNPs-PDA） nanosystem for the accurate detection of glucose in human serum and whole blood through a simple blending of test samples with ligand-free UCNPs, dopamine, and glucose oxidase （GOx）. Owing to the high affinity of lanthanide ions exposed on the surface of ligand-free UCNPs, dopamine monomers could spontaneously attach to the UCNPs and further polymerize to form a PDA shell resulting in a remarkable upconversion luminescence （UCL） quenching （97.4%） of UCNPs under 980-nm excitation. Such UCL quenching can be effectively inhibited by H2O2 produced from the GOx/glucose enzymatic reaction, thus enabling the detection of H2O2 or glucose based on the UCL quenching/inhibition bioassay. Owing to the highly sensitive UCL response and background-free interference of the UCNPs-PDA nanosystem, we achieved a sensitive, selective, and high-throughput bioassay for glucose in human serum and whole blood, thereby revealing the great potential of the UCNPs-PDA nanosystem for the accurate detection of blood glucose or other HRO2-generated biomolecules in clinical bioassays.
