Three perfluorinated Cu-based metal-organic frameworks (MOFs) were prepared starting from extensively fluorinated biphenyl-based ligands accessed via C-H functionalization. These new materials are highly hydrophobic: with water contact angles of up to 151 ± 1°, they are among the most water-repellent MOFs ever reported.

The adsorption of partially fluorinated amphiphiles on metal/metal oxide surfaces allows for the generation of specifically fluorinated thin-film interfaces. Such surfaces are often compared to polytetrafluoroethylene (PTFE), which exhibits a low surface energy, accompanied by biological and chemical inertness, making perfluorinated interfaces applicable to a wide range of technologies. In thinfilm research, self-assembled monolayers derived from fluorinated alkanethiols (FSAMs) serve as welldefined systems that can be used to evaluate the physical and chemical properties of interfaces produced with varying degrees of fluorination. The characteristics of these surfaces have been attributed to both the chemical composition of the individual molecular adsorbates and the consequent structural features associated with monolayers formed from these unique partially fluorinated adsorbates. Specifically, this review seeks to correlate the structural and interfacial properties of FSAMs on gold with the structure/composition of the fluorinated moiety present in the adsorbed molecules and to highlight how the degree of fluorination influences the interfacial ordering of the individual alkanethiolate chains and the vacuum energy levels of the modified metal substrate. Additionally, the thermal stability of these organic thin films is analyzed as a function of adsorbate structure. Included are highlights of some of the studies in which FSAMs, formed from a variety of new types of surfactants, were used to modify colloidal systems, to generate anti-adhesive materials, and to enhance the stability of fluorinated thin films toward low-energy electron degradation.

Magnetic particles are widely used as signal labels in a variety of biological sensing applications, such as molecular detection and related strategies that rely on ligand-receptor binding. In this review, we explore the fundamental concepts involved in designing magnetic particles for biosensing applications and the techniques used to detect them. First, we briefly describe the magnetic properties that are important for bio-sensing applications and highlight the associated key parameters (such as the starting materials, size, functionalization methods, and bio-conjugation strategies). Subsequently, we focus on magnetic sensing applications that utilize several types of magnetic detection techniques: spintronic sensors, nuclear magnetic resonance (NMR) sensors, superconducting quantum interference devices (SQUIDs), sensors based on the atomic magnetometer (AM), and others. From the studies reported, we note that the size of the MPs is one of the most important factors in choosing a sensing technique.

The presence of surface dipoles in self-assembled monolayers (SAMs) gives rise to profound effects on the interfacial properties of the films. For example, CF3-terminated alkanethiolate films are surprisingly more wettable toward polar contacting liquids than analogous hydrocarbon SAMs due to the fluorocarbon-to-hydrocarbon transition (CF3–CH2) at the interface (i.e., the presence of a strong “FC–HC” surface dipole). This report explores the converse situation by analyzing partially fluorinated monolayers (FSAMs) in which the polarity of the surface dipole has been inverted through the creation of an “HC–FC” surface dipole. Thus, a new series of methyl-capped partially fluorinated alkanethiols, CH3(CF2)6(CH2) n SH (where n = 10–13), were designed and synthesized. Structural analyses of the new films show that these adsorbates give rise to well-ordered monolayers. As for the wetting behavior of various liquids on these FSAMs, the new films proved to be less hydrophobic than both the corresponding CF3-terminated and hydrocarbon SAMs and more oleophobic than their hydrocarbon counterparts. Furthermore, odd–even trends were observed in the wettability of the nonpolar and polar aprotic liquids on the new films in which the even FSAMs were more wettable than the odd ones for both types of liquids. However, an inverse odd–even trend was observed for polar protic liquids: odd FSAMs were more wettable than even. We attribute this latter effect to the resistance of highly hydrogen-bonded liquid molecules at the liquid–FSAM interface to adopt a more favorable orientation (on the basis of polarity) when in the presence of the inverted HC–FC dipole.

Near-infrared (NIR) absorption spectroscopy provides molecular and chemical information based on overtones and combination bands of the fundamental vibrational modes in the infrared wavelengths. However, the sensitivity of NIR absorption measurement is limited by the generally weak absorption and the relatively poor detector performance compared to other wavelength ranges. To overcome these barriers, we have developed a novel technique to simultaneously obtain chemical and refractive index sensing in 1-2.5 μm NIR wavelength range on nanoporous gold (NPG) disks, which feature high-density plasmonic hot-spots of localized electric field enhancement. For the first time, surface-enhanced near-infrared absorption (SENIRA) spectroscopy has been demonstrated for high sensitivity chemical detection. With a self-assembled monolayer (SAM) of octadecanethiol (ODT), an enhancement factor (EF) of up to ∼10(4) has been demonstrated for the first C-H combination band at 2400 nm using NPG disk with 600 nm diameter. Together with localized surface plasmon resonance (LSPR) extinction spectroscopy, simultaneous sensing of sample refractive index has been achieved for the first time. The performance of this technique has been evaluated using various hydrocarbon compounds and crude oil samples.