Monthly Archives: November 2017

Temperature independent refractive index measurement using a fiber Bragg grating on abrupt tapered tip

27 November 2017:

Temperature independent refractive index measurement using a fiber Bragg grating on abrupt tapered tip
André D. Gomesa, Beatriz Silveira, Stephen C. Warren-Smith, Martin Becker, Manfred Rothhardt, Orlando Frazão;
Optics & Laser Technology;

Structures, bioactivities and future prospective of polysaccharides from Morus alba

23 November 2017:

Structures, bioactivities and future prospective of polysaccharides from Morus alba (white mulberry): A review;
Xirui He, Jiacheng Fang, Yinlan Ruan, Xiaoxiao Wang, Yin Sun,Ni Wu,Zefeng Zhao, Yu Chang, Ning Ning, Hao Guo, Linhong Huang;
Food Chemistry; DOI:10.1016/j.foodchem.2017.11.084

Biosynthetically Guided Structure–Activity Relationship Studies of Merochlorin A

23 November 2017:

Biosynthetically Guided Structure–Activity Relationship Studies of Merochlorin A, an Antibiotic Marine Natural Product;
Borja López-Pérez, Henry P. Pepper, Rong Ma, Benjamin J. Fawcett, Ashok D. Pehere, Qi Wei, Zengchun Ji, Steven W. Polyak, Huanqin Dai, Fuhang Song, Andrew D. Abell, Lixin Zhang, Jonathan H. George;
ChemMedChem; DOI:10.1002/cmdc.201700 451.

New hybrid sensor developed

21 November 2017:

A new hybrid sensor combining an organic fluorescent probe bound to a nanodiamond has been developed by CNBP researchers (lead author Dr Malcolm Purdey pictured). Able to detect hydrogen peroxide, the sensor is non-toxic and is also highly photostable.

Journal: Scientific Reports.

Publication title: An organic fluorophore-nanodiamond hybrid sensor for photostable imaging and orthogonal, on-demand biosensing.

Authors: Malcolm S. Purdey, Patrick K. Capon, Benjamin J. Pullen, Philipp Reineck, Nisha Schwarz, Peter J. Psaltis, Stephen J. Nicholls, Brant C. Gibson & Andrew D. Abell.

Abstract: Organic fluorescent probes are widely used to detect key biomolecules; however, they often lack the photostability required for extended intracellular imaging. Here we report a new hybrid nanomaterial (peroxynanosensor, PNS), consisting of an organic fluorescent probe bound to a nanodiamond, that overcomes this limitation to allow concurrent and extended cell-based imaging of the nanodiamond and ratiometric detection of hydrogen peroxide. Far-red fluorescence of the nanodiamond offers continuous monitoring without photobleaching, while the green fluorescence of the organic fluorescent probe attached to the nanodiamond surface detects hydrogen peroxide on demand. PNS detects basal production of hydrogen peroxide within M1 polarised macrophages and does not affect macrophage growth during prolonged co-incubation. This nanosensor can be used for extended bio-imaging not previously possible with an organic fluorescent probe, and is spectrally compatible with both Hoechst 33342 and MitoTracker Orange stains for hyperspectral imaging.

New unmixing method to detect and measure fluorophores

17 November 2017:

A new CNBP paper “Statistically strong label-free quantitative identification of native fluorophores in a biological sample,” by Saabah B. Mahbub (first author pictured), Martin Plöschner, Martin E. Gosnell, Ayad G. Anwer and Ewa M. Goldys has just been published in Scientific Reports and is available online.

This work addresses a genuine shortage of methods for real-time continuous monitoring of biochemistry of cells and tissues, especially live cells. Saabah Mahbub and team developed an automated and unbiased unmixing methodology to non-invasively detect the presence and spatial distributions of endogenous fluorophores in retina cells. The method was validated on artificial images, where the addition of a varying known level of noise has allowed to quantify the accuracy of spectral unmixing.

With its capability for high throughput, automation and embedded compatibility with statistical analysis this work will contribute to improved quantification and objectivity in biomedical research.

Microfluidic droplet extraction

16 November 2017:

CNBP and Macquarie University PhD candidate Shilun Feng is first author on a new paper exploring a ‘membrane-on-a-chip’ device. The technology has the potential to form an integral part of a new type of microneedle that would be able to transport tiny and precise amounts of fluid/medication within the body.

Journal: Micromachines.

Publication titleMicrofluidic Droplet Extraction by Hydrophilic Membrane.

Authors: Shilun Feng, Micheal N. Nguyen, and David W. Inglis.

Abstract: Droplet-based microfluidics are capable of transporting very small amounts of fluid over long distances. This characteristic may be applied to conventional fluid delivery using needles if droplets can be reliably expelled from a microfluidic channel. In this paper, we demonstrate a system for the extraction of water droplets from an oil-phase in a polymer microfluidic device. A hydrophilic membrane with a strong preference for water over oil is integrated into a droplet microfluidic system and observed to allow the passage of the transported aqueous phase droplets while blocking the continuous phase. The oil breakthrough pressure of the membrane was observed to be 250 ± 20 kPa, a much greater pressure than anywhere within the microfluidic channel, thereby eliminating the possibility that oil will leak from the microchannel, a critical parameter if droplet transport is to be used in needle-based drug delivery.