查找使用阿拉丁产品的科研文献

Gold nanoparticles-decorated M13 phage SPR probe for dual detection of antigen biomarkers in serum

Jinxiu Hou,Yi Xu,Shasha Sun,Xiaoli Zhong,Chih-Tsung Yang,Xin Zhou

Label-free SPR is rarely used for biomarker detection in real samples due to its low sensitivity. Herein, we report a phage-based SPR (P-SPR) strategy for the detection of carcinoembryonic antigen (CEA) in undiluted serums. M13 phage is genetically engineered to display an anti-CEA single-chain variable region fragment on pIII protein for antigen targeting and to display the gold binding peptide (GBP) at the pVIII protein for gold nanoparticles (GNPs) binding to form the GNPs decorated M13 phage probe that can amplify the plasmon resonance signal. The proposed P-SPR method demonstrated ultrasensitive detection of CEA within 10 min. Under ideal conditions, P-SPR showed exceptional sensitivity with a limit of detection (LOD) of 0.83 fM, which is approximately 2000 times that of the conventional SPR and four orders of magnitude more sensitive than enzyme-linked immunosorbent assay. In particular, the proposed strategy can cross-validate the SPR results through naked-eye counting of the plaques generated by the P-SPR probes, enabling a reliable dual detection system. In addition, P-SPR scheme has excellent sensing performance for the detection of real samples at concentrations lower than LOD of ELISA. Therefore, the proposed P-SPR strategy holds potential for early detection of tumour biomarkers in liquid biopsy.

Enhancement of sensitivity in SPR detection of fipronil based on an Fe3O4@PDA signal amplification strategy

Yulian Li,Bing Zhang,Li Wang,Haoyuan Cai

The detection of fipronil (FPN), a widely used insecticide, in environmental and food matrices is crucial owing to its possible harmful repercussions on human health and ecological systems. This study introduces an innovative signal amplification strategy employing Fe3O4@polydopamine (Fe3O4@PDA) nanoparticles to substantially augment SPR sensitivity in FPN detection and enhance the overall detection performance. Utilizing an indirect competitive inhibition assay, we constructed a sensing platform in which antigens were immobilized on a PDA-modified gold film integrated with reduced gold nanoparticles (AuNPs). Concurrently, fipronil antibodies (FPN-Ab) were conjugated to Fe3O4@PDA, forming magnetic immunoprobes that facilitate the precise capture, magnetic separation, and enrichment of FPN. This methodology achieved a limit of detection (LOD) of 0.52 nM and a half-maximal inhibitory concentration (IC50) of 30.10 nM within a linear range of 18.3–146.4 nM. Experimental results validated the method's efficacy in quantifying FPN residues in real samples, including milk and tap water, demonstrating excellent repeatability and specificity. These findings underscore the potential of the Fe3O4@PDA-based SPR platform as an ultrasensitive and dependable means for FPN detection in diverse environmental and food matrices, addressing the critical need for accurate and efficient monitoring of pesticide residues.

High-Performance Optical Fiber SPR Biosensor for Label-Free Detection of miRNA-588 Toward Osteosarcoma Diagnosis

Xiaohan Chen,Peng Song,Yihao Wang,Chuanquan Wang,Liyun Ding,Xi Chen,Ning Wang

Osteosarcoma is a malignant bone tumor for which diagnosis is critical to patient prognosis. MicroRNA-588 is downregulated in osteosarcoma, highlighting its potential as a diagnostic biomarker. However, its low abundance in body fluids makes sensitive detection difficult. This study presents a label-free reflective optical fiber surface plasmon resonance (SPR) biosensor with optimized probe immobilization for ultrasensitive miRNA-588 detection in serum. The sensor utilizes plasmonic coupling between a gold film and gold nanoparticles to enhance the SPR response. By incorporating an A 15 anchor and a T 5 spacer into a single oligonucleotide, the A 15 T 5 probe promotes a more upright presentation of the recognition sequence while simplifying interface construction. Among the configurations evaluated, the A 15 T 5 probe showed the best performance for miRNA-588 detection. The biosensor exhibits a wide detection range from 10 −15 to 10 −7 M, with a low detection limit (LOD) of 1.12 × 10 −17 M, along with good stability and repeatability. In clinical sample testing, the sensor achieved an area under the receiver operating characteristic (ROC) curve of 0.95 and showed greater diagnostic discrimination than serum alkaline phosphatase in the evaluated cohort. This platform enables high-sensitivity detection of trace biomarkers, supporting the diagnosis of major diseases.

Fiber-optic SPR sensor based on molecularly imprinted polymers for detection of perfluorooctane sulfonate in water

Hongyou Wu,Bin Liu,Yingying Hu,Juan Liu,Hong Yang,Yue Fu,Yue Zhang,Tao Wu,Ran Tao,Shi Qiu,Jinhui Yuan,Qiang Wu

A novel MNM fiber SPR sensor integrated with APTES-modified MIPs is developed for highly specific PFOS recognition. • PFOS LoD is 0.84 pg/mL over concentration range of 1 pg/mL to 10 ng/mL. • Validated detection to spiked PFOS in tap and lake water with recover rates of 79.00% ~114.70%. Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely present in aquatic environments, posing a severe risk to human health due to its bioaccumulation and toxicity. To address the urgent need for sensitive on-site detection of PFOS, this study developed a fiber-optic surface plasmon resonance (SPR) sensor based on a multimode-no-core-multimode fiber structure. By immobilizing PFOS- selective molecularly imprinted polymers (MIPs) onto the gold surface, the sensor achieved good sensitivity and long-term stability. Experimental results show that the proposed sensor has an ultra-low limit of detection (LoD) of 0.84 pg/mL and a wide dynamic linear measurement range from 1 pg/mL to 10 ng/mL (R 2  = 0.9933), outperforming most reported optical/colorimetric PFOS sensors. Furthermore, the sensor exhibited excellent selectivity, satisfactory repeatability (relative standard deviation = 4.63%), and good practical applicability, requiring only simple filtration pretreatment to achieve spiked recovery rates of 79.00%–114.70% in tap and lake water samples. These results highlight the sensor's great potential for on-site PFOS monitoring in complex aquatic environments. Download: Download high-res image (143KB) Download: Download full-size image

Dual-mode SPR sensing with surface and bulk refractive index decoupling via hybrid gap plasmonic architecture

Runcheng Liu,Jie Yan,Wen Yang,Mingshun Jiang

A fundamental challenge in surface plasmon resonance (SPR) sensing arises from the mutual interference between surface refractive index and bulk refractive index responses. In practice, strong plasmonic excitation and reliable bulk refractive index referencing are rarely compatible within a single sensing configuration. To address this long-standing limitation, we develop a high-performance tilted fiber Bragg grating (TFBG)-SPR sensing platform based on a hybrid gap-plasmonic architecture. By limiting the gold film thickness to 30 nm, evanescent field tunneling is retained, allowing the cutoff cladding mode to be excited and employed as an intrinsic bulk refractive index reference. The accompanying loss of plasmonic confinement associated with such thin coatings is compensated by the introduction of gold nanoparticles (AuNP) together with a thickness-tunable two-dimensional metal–organic framework (MOF) spacer. This combination promotes strong hybridization between localized and propagating plasmonic modes, creating nanoscale gaps that concentrate electromagnetic energy at the sensing interface. As a consequence, the SPR quality is substantially improved, while interference from the surrounding bulk medium is effectively suppressed. With this architecture, the platform achieves an amplitude sensitivity of 3925 dB/RIU, corresponding to a 2.28-fold enhancement relative to conventional gold-coated TFBG, while preserving stable self-referencing capability. The robustness of the dual-mode self-decoupling mechanism is further demonstrated through selective detection of Hg 2+ ions, in which weak surface-binding signals are reliably resolved in real time against background bulk fluctuations. These results establish a general and practical strategy for reconciling high sensitivity with robust surface and bulk signal decoupling in fiber-optic plasmonic sensing platforms.

An automated fiber-optic SPR platform with a self-assembled peptide interface for sPD-L1 analysis

Huiling Wu,Wanqing Yu,Pengwei Zhao,Xiaorui Liu,Yeting Zhang,Hai Han,Qiqin Wang,Zhengjin Jiang,Jia-Huan Qu

An automated FO-SPR method is established for sPD-L1 quantification. • The EMP interface self-assembles on FO-probes via terminal cysteines. • The functionalized probes retained > 90% of their initial response after 4 weeks at 4 °C. • sPD-L1 detection is achieved in diluted human serum via Ab-AuNP amplification. An automated dip-probe fiber-optic surface plasmon resonance (FO-SPR) method was developed for soluble programmed death-ligand 1 (sPD-L1) quantification. The system employs a one-step self-assembled epitope-mimicking peptide (EMP) as the capture element. Through a terminal cysteine, the EMP binds directly onto the gold probe to form a capture interface, eliminating the need for chemical cross-linking. Coupled with an antibody-conjugated gold nanoparticle (Ab-AuNP) sandwich assay, the FO-SPR platform achieved a limit of detection of 20.5 ng/mL in diluted human serum with recoveries ranging from 93.7% to 106.6%. Independently prepared probes yielded intra- and inter-assay relative standard deviations below 6%, and EMP-functionalized probes retained more than 90% of their initial response after four weeks of storage at 4 °C. By pairing this peptide interface with a direct-immersion format that avoids fluidic clogging, this work delivers a practical and automated FO-SPR methodology for diverse bioanalytical applications. Download: Download high-res image (122KB) Download: Download full-size image

Study of cell and drug interactions based on dual-mode detection using SPR and fluorescence imaging

Lulu Zhang,Runye Liu,Luyao Liu,Xiaoxing Xing,Haoyuan Cai,Yongdong Fu,Jianhai Sun,Wang Ruan,Jian Chen,Xianbo Qiu,Duli Yu

The investigation of the interactions between cells and drugs forms a crucial aspect of biological and clinical medical studies. Generally, single-cell or local-cellular studies require a microscopic imaging system with high magnifications, which suffers from low detection throughputs and poor time responses. The study presented in this paper combined SPR and fluorescence to achieve cell localization, real-time monitoring of cell images and quantitative analysis of drugs. In order to obtain more comprehensive, accurate and real-time data, a dual-mode system based on surface plasmon resonance (SPR) and fluorescence was constructed based on a 4× magnification lens. This enables simultaneous studies of an entire cell and a specific region of the cell membrane. An adaptive adjustment algorithm was established for distorted SPR images, achieving temporal and spatial matching of the dual-mode detection. The combination of SPR and fluorescence not only achieved micro-detection but also complemented the qualitative or quantitative limitations of SPR or fluorescence method alone. In system characterization, the response signal of SPR was noticed to increase with the increasing concentration of EGF in stimulated cells. It indicated that this platform could be employed for quantitative detection of the cell membrane region. Upon addition of EGF, a peak in the SPR curve was observed, and the cells in the corresponding SPR image turned whiter. This indicated that the platform can simultaneously monitor the SPR response signal and image changes. The response time of fluorescence in EGF testing was several seconds earlier than SPR, revealing that signal transduction first occurred in the whole cell and then propagated to the cell membrane region. The inhibitory ability of Gefitinib on cells was verified in a fast and real-time manner within 20 min. The results indicated that the detection limit of this method was 20 IU/mL for EGF and 10 µg/mL for Gefitinib. In conclusion, this study demonstrates the advantages of SPR and fluorescence dual-mode techniques in the analysis of cell-drug interactions, as well as their strong potential in drug screening.

Plug-in optical fiber SPR biosensor for lung cancer gene detection with temperature and pH compensation

Xuegang Li,Pengqi Gong,Qiming Zhao,Xue Zhou,Yanan Zhang,Yong Zhao

A novel DNA hybridization optical fiber sensor with temperature and pH compensation for detecting a common lung cancer gene of epidermal growth factor receptor (EGFR) gene was demonstrated in this paper. The paper proposes the first research to achieve dual surface plasmon resonance (SPR) in an Fiber Bragg grating (FBG) and implement a three-parameter detection of DNA sequence , temperature and pH using a single fiber. Probe DNA sequences (pDNA) and PAA/CS, a pH-sensitive material, are immobilized on the sensor surface for EGFR gene exon-20 detection and temperature and pH monitoring simultaneously. The effectiveness of this functionalized method has been proved by using an atomic force microscope (AFM) and scanning electron microscope (SEM). The limit of detection (LOD) of EGFR gene was experimentally verified to 13.5 nM. The advantages of fast response, high sensitivity, label free, plug in, low LOD and three-parameter detection demonstrated by this sensor in the experiment are important for the field of DNA hybridization research and solving the problems of biosensor susceptibility to temperature and pH.

WS₂–NH₂ Enhanced Fiber SPR Biosensor for Ultralow-Level β-Actin Detection via Cu–Glycine Functionalization

Chen Liu,Xue Zhou,Hanyu Bai,Yana Zhang,Yong Zhao,Xuegang Li

Beta-actin (ACTB), a highly conserved cytoskeletal protein, is frequently dysregulated in early-stage malignancies, making its sensitive and specific detection crucial for cancer screening. Here, we develop a reflective fiber-optic SPR biosensor functionalized with copper–glycine engineered WS₂ nanosheets for label-free ACTB detection. The Cu–glycine modification not only enables WS₂ surface amination for efficient antibody conjugation, but also introduces Cu²⁺-mediated near-infrared absorption to amplify the plasmonic resonance response. Combined with the intrinsically large surface area and high refractive index sensitivity of WS₂, this synergistic design markedly enhances both molecular binding and signal transduction. The resulting WS₂-NH₂-based sensor achieves a refractive index sensitivity of 1467.5 nm/RIU, representing a 1.67-fold enhancement over unmodified fiber probes. For ACTB detection, it delivers an ultralow detection limit down to 9.766 pM, a broadened linear range of 2.4–120 pM (5×expansion), and a biosensing sensitivity of 84.477 nm/nM (1.4× improvement). Furthermore, at 1 ng/mL, a rapid response time of 20 min is achieved, demonstrating applicability for trace-level biomarker screening. Integrating high sensitivity, broad dynamic range, amplified spectral response, and strong anti-interference capability, this plasmonic WS₂-NH₂-modified fiber platform enables highly selective, label-free ACTB quantification. These findings highlight its strong potential for early cancer diagnosis, biomarker monitoring, and precision medical applications.

A SPR aptamer sensor for mercury based on AuNPs@NaYF4:Yb,Tm,Gd upconversion luminescent nanoparticles

Bo Ling,Yuanhui Ma,Hongqi Chen,Lun Wang

A new aptamer-based surface plasmon resonance (SPR) system has been designed to detect Hg2+ that utilizes near-infrared (NIR)-to-NIR gold nanoparticle coated NaYF4:Yb,Tm,Gd up-conversion nanoparticles (AuNPs@NaYF4:Yb,Tm,Gd UCNPs) as probes. The AuNPs@NaYF4:Yb,Tm,Gd UCNPs were prepared and excited by near-infrared light (980 nm) which emitted at a near-infrared wavelength (808 nm) using an inexpensive infrared continuous wave laser diode. The AuNPs@NaYF4:Yb,Tm,Gd UCNPs were conjugated with Hg2+ aptamers. In the presence of Hg2+, the AuNPs@NaYF4:Yb,Tm,Gd UCNPs were brought into close proximity because of the formation of T–Hg2+–T base pairs. Then the luminescence enhanced because of the plasmon resonance effects. Based on this, a new SPR system was developed for the detection of Hg2+ that had high sensitivity and selectivity in the NIR region. This method was successfully applied to detect Hg2+ concentration in real samples.

A lipase-conjugated carbon nanotube fiber-optic SPR sensor for sensitive and specific detection of tributyrin

Hongxin Zhang,Xuegang Li,Xue Zhou,Yanan Zhang,Yong Zhao

As a low-density lipoprotein, tributyrin plays an essential role in food safety and human health. In this study, a novel lipase-conjugated carbon nanotube (CNT) surface plasmon resonance (SPR) fiber-optic sensor is used to specifically detect tributyrin for the first time. In this work, CNTs can be used as an amplifying material to significantly increase the sensitivity of SPR sensors due to their high refractive index and large surface area. CNTs can also be used as an enzyme carrier to provide abundant carboxyl groups for the specific binding of lipases. Covering the surface of the sensor with CNTs can not only enhance the performance of the sensor, but also provide sufficient detection sites for subsequent biomass detection, reduce the functionalization steps, and simplify the sensor preparation process. The experimental results demonstrate that the refractive index sensitivity of the traditional multimode fiber (MMF)–single mode fiber (SMF)–MMF transmissive optical fiber sensor is 1705 nm RIU−1. After covering the sensor with CNTs, the sensitivity is 2077 nm RIU−1, and the sensitivity has been improved very well. In addition, there are abundant functional groups on CNTs, which can provide abundant binding sites. Conjugating lipase on carbon nanotubes helps to achieve linear detection in the range of 0.5 mM to 4 mM tributyrin, with a sensitivity of 4.45 nm mM−1 and a detection limit of 0.34 mM, which is below the 2.26 mM detection standard and meets food safety monitoring requirements. Compared with other sensors, the optical fiber biosensor proposed in this study expands the concentration detection range of tributyrin. Furthermore, the sensor also has good stability, anti-interference performance and specificity. Therefore, the sensor proposed in this paper has good application prospects in the fields of food safety and biomedicine.

Optical Fiber SPR Sensor With Surface Ion Imprinting for Highly Sensitive and Highly Selective Ni2+ Detection

Yao Ma,Wanlu Zheng,Ya-Nan Zhang,Xuegang Li,Yong Zhao