ACS Sensors最新文献

Recent examples of immune responses directed against the synthetic polymer poly(ethylene glycol) (PEG) have led to the development of biocompatible polymers, which are viewed as promising candidates to act as surrogate materials for use in biological applications, such as hydrophilic poly(2-oxazoline)s (POx). Despite this, the characterization of critical aspects of the immune response against these emerging materials is sparse, in part because no known monoclonal antibodies (mAbs) against this family of synthetic material have been reported. To advance the understanding of such responses, we report the successful isolation and characterization of hybridoma-derived mAbs with excellent specificity for different POx species and notable selectivity for highly branched polymer architectures over linear systems. In conjunction with established mAbs targeted against PEG, we show that these antibodies can be employed for sensitive in vivo multiplex-detection of label-free polymer therapeutics based on the specificity of the polymer-antibody binding. This approach enables scalable therapeutic drug monitoring of multiple polymer therapeutics within a single animal, simultaneously.

Flexible capacitive pressure sensors are now widely used in the fields of electronic skin, medical monitoring, and human-computer interaction. However, most of the current flexible capacitive pressure sensors generally suffer easy saturation and low sensitivity under high pressure. This paper proposes a new strategy using evenly distributed spiked nickel (Ni) particles as fillers in a nanofiber membrane to prepare flexible capacitive pressure sensors. The spiked Ni particles are embedded into the interior of polyimide (PI) electrospun nanofiber membranes by electrostatic self-assembly. The experimental results show that the introduction of spiked Ni particles effectively increased the sensitivity of the sensor under high pressure due to the formation of many parallel microcapacitors. In addition, a novel combination method is adopted to integrate individual sensor modules into arbitrary sensor arrays for sensing field pressures. Specifically, the sensor prototype with a 2.7 weight ratio of spiked nickel/PI nanofiber membranes was characterized by short response/recovery times (30/40 ms), wide pressure detection range (1.5 MPa), and excellent mechanical stability (1000 cycles), more than 4-fold increase in sensor sensitivity (4.04 MPa^-1 at 0-1.5 MPa) compared to pure PI nanofiber membrane dielectric layers. Due to its superior performance demonstration, the sensor could be applied in many scenarios, such as human motion detection, sleeping posture monitoring, and plantar pressure measurement, indicating good application prospects in diverse wearable systems.

This paper presents a compact all-fiber multicomponent gas Raman probe using a dual-fiber architecture within a platinum-coated capillary. The probe eliminates the need for conventional optical components like filters and dichroic mirrors by strategically employing metal coating on the excitation fiber's surface to suppress interference signals. A detailed analysis of the silica Raman signal and fluorescence propagation within the system facilitated this design. Metal-coated capillary (MCC), produced via atomic layer deposition (ALD) of platinum on silica capillaries, exhibits excellent optical properties and environmental resilience, boosting gas Raman signal reception. Careful alignment of the dual fibers relative to the platinum-coated capillary optimizes signal-to-noise ratio enhancement. The system achieves detection limits of 21 ppm for CH₄, 30 ppm for C₂H₄, and 51 ppm for C₂H₆ within 45 s of exposure, alongside a rapid response time of 25 s (relative to systems based on hollow-core antiresonant fibers) and robust stability. Its streamlined optical path and compact design enhance practicality across diverse fields, including agriculture, industry, environmental monitoring, and healthcare, advancing multicomponent gas detection technology.

High sensitivity, low concentration, and excellent selectivity are pronounced primary challenges for semiconductor gas sensors to monitor acetone from exhaled breath. In this study, nitrogen-doped carbon quantum dots (N-CQDs) with high reactivity were used to activate dandelion-like hierarchical tungsten oxide (WO₃) microspheres to construct an efficient and stable acetone gas sensor. Benefiting from the synergistic effect of both the abundant active sites provided by the unique dandelion-like hierarchical structure and the high reaction potential generated by the sensitization of the N-CQDs, the resulting 16 wt % N-CQDs/WO₃ sensor shows an ultrahigh response value (R_a/R_g = 74@1 ppm acetone), low detection limit (0.05 ppm), outstanding selectivity, and reliable stability to acetone at the optimum working temperature of 210 °C. Noteworthy that the N-CQDs facilitate the carrier migration and intensify the reaction between acetone and WO₃ during the sensing process. Considering the above advantages, N-CQDs as a sensitizer to achieve excellent gas-sensitive properties of WO₃ are a promising new strategy for achieving accurate acetone detection in real time and facilitating the development of portable human-exhaled gas sensors.

Circular RNAs (circRNAs), as a class of noncoding RNA molecules with a circular structure exhibit high stability and spatiotemporal-specific expression, making them ideal cancer biomarkers for liquid biopsy. Herein, a new photoelectrochemical (PEC) biosensor for a highly sensitive circRNA assay in the whole blood of lung cancer patients was designed based on CRISPR/Cas13a-programmed Cu nanoclusters (Cu NCs) and a Z-scheme covalent organic framework/silver sulfide (T-COF/Ag₂S) composite. This Z-scheme T-COF/Ag₂S composite accelerates electron transfer and produces an excellent initial photocurrent. When CRISPR/Cas13a precisely targets circRNA, it nonspecifically cleaves the triple-helix molecular structure to release DNA fragments (C'/C"). After the C'/C" opens the DNA hairpin probe (HP) modified on the electrode, hybridization chain reactions are performed to produce abundant AT-rich double-stranded DNA with the addition of H1 and H2 probes. Upon the incubation of Cu²⁺, Cu NCs are in situ formed via the A-Cu²⁺-T bonds and can effectively quench the photocurrent of the Z-scheme T-COF/Ag₂S due to the energy transfer process. This developed PEC biosensor for the circRNA assay shows a low limit of detection of 0.5 fM, and the reusability of DNA-modified magnetic beads (MB-DNA) reduces the detection cost. Moreover, the PEC biosensor can accurately quantify the circRNA level and distinguish the circRNA expression in whole blood from healthy controls and lung cancer patients, offering strong potential in clinical diagnosis.