BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Jianguo Zhang,Shaozhen Wang,Ni Gao,Dexiang Feng,Lun Wang,Hongqi Chen
A new turn-on luminescence energy transfer (LET) system has been designed for the detection of prostate specific antigen (PSA, a cancer marker) that utilizes Mn 2+ -enhanced long wavelength luminescence NaYF 4 : Yb, Er upconversion nanorods as the donor and gold nanorods as the acceptor. The Mn 2+ -doped NaYF 4 :Yb,Er upconversion luminescence nanorods with an emission peak located in the red region were synthesized. The presence of Mn 2+ markedly increased the luminescence intensity over that of the NaYF 4 :Yb, Er upconversion nanomaterials (excited by a 980 nm continuous wavelength laser). The surfaces of Mn 2+ -doped NaYF 4 :Yb, Er upconversion nanorods were modified with poly(acrylic acid). Antibodies against prostate specific antigen were bound to the surface of the carboxyl-functionalized upconversion nanorods, which acted as the energy donor in this LET system. Gold nanorods with an absorption band at ~666 nm were synthesized by the seed growth method, acted as the energy acceptor. The emission band of the upconversion nanorods overlapped well with the absorption band of the gold nanorods. The luminescence was quenched because of the electrostatic interactions that shortened the distance between the donor (negatively charged) and the accepter (positively charged).When the PSA antigen was added into the system, the energy acceptor and the energy donors were separated because the binding affinity between PSA and anti-PSA was greater than the electrostatic interactions, and thereby the luminescence was recovered. The linear range of detecting PSA was from 0.1172 to 18.75 ng/mL ( R =0.995), with a limit of detection for PSA as low as 0.1129 ng/mL. The method was successfully applied to the sensing of PSA in human serum samples.
研究领域:
生物技术
·
纳米技术
·
分析化学
·
癌症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 5
·835-840
·
IF 1.9
Zhongling Gao,Lei Wang,Lun Wang,Hongqi Chen
Long wavelength luminescent NaYF4:Yb,Er/NaGdF4 core–shell upconversion nanoparticles that were synthesized and modified with poly(acrylic acid) (PAA) were used to detect sulfide ions. The NaYF4:Yb,Er/NaGdF4 core–shell upconversion nanoparticles were synthesized to give an emission peak in the red-light region. When the carboxyl-functionalized NaYF4:Yb,Er/NaGdF4 core–shell upconversion nanoparticles and cupric ions (Cu2+) were mixed, the luminescence was quenched because of coordination between the carboxyl of PAA and Cu2+. However, when sulfide ions were added into the system, due to the competitive binding between S2− and Cu2+, the luminescence of the NaYF4:Yb,Er/NaGdF4 core–shell upconversion nanoparticles was recovered. Based on the recovery of the luminescence intensity, a turn-on system for the detection of sulfide ions was designed. Under optimal conditions, the linear range for the detection of sulfide ions ranged from 2.63 × 10−2 to 2.25 × 102 μM (R = 0.99) with a limit of detection for sulfide ions as low as 2.20 × 10−2 μM. The method was successfully applied to sulfide ion sensing in different environments.
研究领域:
纳米技术
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Hongqi Chen,Fei Yuan,Shaozhen Wang,Juan Xu,YiYan Zhang,Lun Wang
In this work, we design a FRET system for sensitive and selective determination of thrombin in red region, in which NaYF 4 :Yb,Er upconversion nanoparticles (UCNPs) act as donor and gold nanorods (Au NRs) act as acceptor. NaYF 4 :Yb,Er UCNPs with a strong emission at 661 nm were successfully synthesized by tuning the doped ions ratio. Carboxyl-functionalized NaYF 4 :Yb,Er UCNPs and Au NRs were then prepared and conjugated with the thrombin aptamers, respectively. The fluorescence emission band of NaYF 4 :Yb,Er UCNPs ( λ max =661 nm) highly overlaps with the absorption band of Au NRs( λ max =666 nm), which benefits from the large tunability of the spectrum band of Au NRs. A FRET system was then formed when thrombin was added to the mixture of NaYF 4 :Yb,Er UCNPs and Au NRs, which were both modified thrombin aptamers. The fluorescence quenching efficiency of NaYF 4 :Yb,Er UCNPs was increased in a thrombin concentration-dependent manner, which built the principle of thrombin quantification. The linear range was 2.5–90 nM in an aqueous buffer, and 3.75–112.5 nM in spiked human serum samples for thrombin. It also demonstrates a high selectivity to other biological species due to the specific binding. The measurement of thrombin in human plasma is satisfying, suggesting that the FRET system is of practical value in a complex biological sample matrix in red region.
研究领域:
分析化学
·
生物传感
·
纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 22
·3296-3301
·
IF 1.9
Lei Wang,Yuan Ji,Yuezhen He,Lun Wang,Hongqi Chen
Li+-Doped NaYF4:Yb,Er upconversion luminescent nanoparticles (UCLNPs) were synthesized and modified with poly(acrylic acid) (PAA). The luminescence of the carboxyl-functionalized UCLNPs at 664 nm was quenched in the presence of cupric ions (Cu2+) due to the coordination of Cu2+ with the carboxyl group of PAA. When pyrophosphate ions (PPi) were added, the luminescence of the UCLNPs was restored due to the competitive binding of PPi with Cu2+. However, pyrophosphatase (PPase) could promote the hydrolysis of PPi, thus releasing Cu2+, leading to requenching of the luminescence. Under optimal conditions, the luminescence response was virtually proportional to the activity of the PPase between 0.500 and 50.0 mU mL−1, and the limit of detection was 0.441 mU mL−1. Based on the competition assay approach, a new highly sensitive method in the red region for real-time detection of PPase activity was developed.
研究领域:
分析化学
·
生物化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）