抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Detection of chemical and biological agents plays a fundamental role in biomedical, forensic and environmental sciences1–4 as well as in anti bioterrorism applications.5–7 The development of highly sensitive, cost effective, miniature sensors is therefore in high demand which requires advanced technology coupled with fundamental knowledge in chemistry, biology and material sciences.8–13

In general, sensors feature two functional components: a recognition element to provide selective/specific binding with the target analytes and a transducer component for signaling the binding event. An efficient sensor relies heavily on these two essential components for the recognition process in terms of response time, signal to noise (S/N) ratio, selectivity and limits of detection (LOD).14,15 Therefore, designing sensors with higher efficacy depends on the development of novel materials to improve both the recognition and transduction processes. Nanomaterials feature unique physicochemical properties that can be of great utility in creating new recognition and transduction processes for chemical and biological sensors15–27 as well as improving the S/N ratio by miniaturization of the sensor elements.28

Gold nanoparticles (AuNPs) possess distinct physical and chemical attributes that make them excellent scaffolds for the fabrication of novel chemical and biological sensors (Figure 1).29–36 First, AuNPs can be synthesized in a straightforward manner and can be made highly stable. Second, they possess unique optoelectronic properties. Third, they provide high surface-to-volume ratio with excellent biocompatibility using appropriate ligands.30 Fourth, these properties of AuNPs can be readily tuned varying their size, shape and the surrounding chemical environment. For example, the binding event between recognition element and the analyte can alter physicochemical properties of transducer AuNPs, such as plasmon resonance absorption, conductivity, redox behavior, etc. that in turn can generate a detectable response signal. Finally, AuNPs offer a suitable platform for multi-functionalization with a wide range of organic or biological ligands for the selective binding and detection of small molecules and biological targets.30–32,36 Each of these attributes of AuNPs has allowed researchers to develop novel sensing strategies with improved sensitivity, stability and selectivity. In the last decade of research, the advent of AuNP as a sensory element provided us a broad spectrum of innovative approaches for the detection of metal ions, small molecules, proteins, nucleic acids, malignant cells, etc. in a rapid and efficient manner.37



Figure 1

Physical properties of AuNPs and schematic illustration of an AuNP-based detection system.



In this current review, we have highlighted the several synthetic routes and properties of AuNPs that make them excellent probes for different sensing strategies. Furthermore, we will discuss various sensing strategies and major advances in the last two decades of research utilizing AuNPs in the detection of variety of target analytes including metal ions, organic molecules, proteins, nucleic acids, and microorganisms.

/pdf/gold-nanoparticles-in-chemical-and-biological-sensing-5e2qojkdzn.pdf

Gold nanoparticles in chemical and biological sensing.

Polydopamine and Its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields

Aggregation-induced emission: phenomenon, mechanism and applications.

Core/Shell Nanoparticles: Classes, Properties, Synthesis Mechanisms, Characterization, and Applications

Gold nanoparticles in delivery applications

The wide variety of core materials available, coupled with tunable surface properties, make nanoparticles an excellent platform for a broad range of biological and biomedical applications. This Review provides an introduction to nanoparticle–biomolecular interactions as well as recent applications of nanoparticles in biological sensing, delivery, and imaging of live cells and tissues.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.200703183

Applications of Nanoparticles in Biology

The near-infrared (NIR) window refers to a range of wavelengths (700–1300 nm) in which biological tissues are highly transparent.[1] Consequently, biological imaging and therapy modalities employ light at these wavelengths for the monitoring[1] and triggering[2] of biological events in vitro and in vivo. For instance, photothermal ablation takes advantage of NIR absorbing materials for transducing light into heat.[2] The resultant thermal energy can be used for a number of applications, such as tissue ablation and drug release. Despite the intense interest in NIR photothermal agents, their development has suffered from considerable challenges. In particular, few nanomaterials display the requisite absorption profiles required for NIR photothermal transduction.

/pdf/chemically-exfoliated-mos2-as-near-infrared-photothermal-4schq8vof6.pdf

Chemically Exfoliated MoS2 as Near-Infrared Photothermal Agents

MoS2 is a two-dimensional material that is gaining prominence due to its unique electronic and chemical properties. Here, we demonstrate ligand conjugation of chemically exfoliated MoS2 using thiol chemistry. With this method, we modulate the ζ-potential and colloidal stability of MoS2 sheets through ligand designs, thus enabling its usage as a selective artificial protein receptor for β-galactosidase. The facile thiol functionalization route opens the door for surface modifications of solution processable MoS2 sheets.

Ligand Conjugation of Chemically Exfoliated MoS2

There is a direct correlation between protein levels and disease states in human serum, which makes it an attractive target for sensors and diagnostics. However, this is challenging because serum features more than 20,000 proteins, with an overall protein content greater than 1 mM. Here we report a sensor based on a hybrid synthetic-biomolecule that uses arrays of green fluorescent protein and nanoparticles to detect proteins at biorelevant concentrations in both buffer and human serum. Distinct and reproducible fluorescence-response patterns were obtained from five serum proteins (human serum albumin, immunoglobulin G, transferrin, fibrinogen and a-antitrypsin), both in buffer and when spiked into human serum. Using linear discriminant analysis we identified these proteins with an identification accuracy of 100% in buffer and 97% in human serum. The arrays were also able to discriminate between different concentrations of the same protein, as well as a mixture of different proteins in human serum.

/pdf/sensing-of-proteins-in-human-serum-using-conjugates-of-3axi9aomla.pdf

Mrinmoy De

Papers

Gold nanoparticles in delivery applications

Applications of Nanoparticles in Biology

Chemically Exfoliated MoS2 as Near-Infrared Photothermal Agents

Ligand Conjugation of Chemically Exfoliated MoS2

Sensing of proteins in human serum using conjugates of nanoparticles and green fluorescent protein.