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Optical fiber tweezers offer a simple, low-cost and portable solution for non-invasive trapping and manipulation of particles. However, single-fiber tweezers require fiber tip modification (tapering, lensing, etc.) and the dual-fiber approach demands strict alignment and positioning of fibers for robust trapping of particles. In addition, both tweezing techniques offer a limited range of particle manipulation and operate in low flow velocity regimes (a few 100 μm s−1) when integrated with microfluidic devices. In this paper, we report a novel opto-hydrodynamic fiber tweezers (OHT) platform that exploits the balance between the hydrodynamic drag force and optical scattering forces to trap and manipulate single or multiple particles of various shapes, sizes, and material compositions in a microfluidic channel. 3D hydrodynamic flow focusing offers an easy and dynamic alignment of the particle trajectories with the optical axis of the fiber, which enables robust trapping of particles with high efficiency of >70% and throughput of 14 particles per minute (operating flow velocity: 1000 μm s−1) without the need for precision stages or complex fabrication. By regulating the optical power and flow rates, we were able to trap single particles at desired positions in the channel with a precision of ±10 μm as well as manipulate them over a long range upstream or downstream with a maximum distance of 500 μm. Our opto-hydrodynamic tweezers offer an alternative to conventional optical fiber tweezers for several applications in physics, biology, medicine, etc. [ABSTRACT FROM AUTHOR]

Advancements in health care monitoring demand a rapid, accurate and reliable early diagnosis of "Heart Attack" (acute myocardial infarction) with an objective to develop a cost-effective, rapid and label-free point of care diagnostic test kit for the detection of cardiac troponin I (cTnI) on paper-based multi-frequency impedimetric transducers. Paper based sensing platforms were developed by integrating carboxyl group functionalized multi-walled carbon nanotubes (MWCNT) with antibodies of cardiac troponin I (anti-cTnI) biomarker and was characterized using Electrochemical Impedance Spectroscopy (EIS). Various concentrations of cTnI with anti cTnI were studied as a function of impedance change. The suitability of the proposed immunosensor is demonstrated by spiking cTnI in blood serum samples. The limit of detection (LoD) and sensitivity of the proposed sensor was determined to be 0.05 ng/mL and 1.85 mΩ/ng/mL respectively, with a response time of ~1 min. The shelf life of the fabricated sensor was nearly 30 days. The rapid response, very low detection limit, and cost effectiveness offer a portable platform to detect cTnI in blood serum samples. The proposed immunosensor, therefore, offers an affordable healthcare diagnostic platform in resource limited areas. [ABSTRACT FROM AUTHOR]

Graphene and its variants have garnered significant attention in the scientific community due to their distinctive characteristics at the nanoscale. The unique properties of graphene such as exceptional electrical, mechanical, optical, and thermal features, make it particularly significant. These nanomaterials, given their unique properties and adaptability to biocompatibility, are gaining popularity in a diverse range of biomedical applications. These nanomaterials have the potential to advance the field of biomedicine, with the emergence of novel nanomaterials acting as a crucial catalyst. Recent developments have highlighted the broad applications of these nanomaterials in biological research. This article provides a concise analysis of the techniques employed in the production of graphene and its various forms. Subsequently, the characterization techniques, toxicity, safety concerns, and factors determining their potential applicability in the realm of biomedicine are discussed. This review focuses on the recent utilization of graphene-based nanomaterials in tissue engineering, drug delivery, biosensing, bioimaging, and other related studies. [Display omitted] • Safety considerations in biomedical applications. • Specific modifications and functionalization of graphene. • Graphene-based biomedical devices. • Exploration of the biodegradability and safety aspects of graphene-based materials. [ABSTRACT FROM AUTHOR]