Prof Shiddiky and his research team are at the forefront of innovation in electrochemistry, biosensing, and point-of-care diagnostics. Their pioneering work has led to the development of cutting-edge diagnostic methods and portable devices capable of rapidly and accurately detecting disease-related molecules, cells, and pathogens. These technologies are regularly published in leading peer-reviewed journals and presented at high-profile international conferences. A selection of videos highlighting these innovations and real-world applications can be found below.

Videos

Xylella fastidiosa is a dangerous plant bacteria that can infect over 350 plant species, causing serious diseases like Pierce’s disease in grapes, citrus variegated chlorosis, and almond leaf scorch. It has already caused billions of dollars in crop losses worldwide and continues to spread rapidly. Although it hasn't yet been found in Australia, the risk is high, so early detection is critical to protect the country’s agriculture and economy.

Current lab-based tests like PCR and LAMP can detect the bacteria, but they are expensive, slow, and require specialised equipment and trained personnel—making them unsuitable for on-site or large-scale use in the field.

This study introduces a new, simple, and cost-effective electrochemical test that can detect the DNA of Xylella fastidiosa quickly and without the need for DNA amplification. The test uses three main steps:

(i) DNA Capture: Special magnetic beads coated with a probe are used to pull out the target DNA from the sample.

(ii) DNA Binding: The captured DNA is then placed on a tiny gold electrode using a mild electric charge.

(iii) Signal Detection: A technique called differential pulse voltammetry (DPV) is used to measure how much DNA is on the electrode. The more DNA present, the lower the current, allowing researchers to determine the amount of bacteria in the sample.

This method avoids the need for expensive lab tools and reagents and gives results more quickly. It is also highly sensitive, specific to X. fastidiosa, and can be used directly in the field with portable equipment.

This is the first time an electrochemical approach has been used for detecting Xylella fastidiosa. The technique could transform plant disease surveillance by providing a faster, more affordable tool for farmers, biosecurity officers, and agricultural workers—especially in remote or resource-limited areas. It may also be adapted for broader use in precision farming and global plant health monitoring.

Farjana Joins MicroTAS 2025 to Share Her Work on Easy-to-Use Biosecurity Testing Tools

This study introduces ExoPorous, a new point-of-care diagnostic platform designed to detect placental exosomal mRNA for the early, non-invasive prediction of pregnancy complications like preeclampsia (PE). The innovation lies in two key components:

(a) ExoPorous Nanomaterials – Newly developed ferric oxide-based magnetic particles with high antibody binding efficiency are used to directly capture placental exosomes (PLAP-positive) from blood samples.

(b) LNA-Modified Molecular Beacon Probes – These improve the accuracy and clarity of RT-LAMP (reverse transcription loop-mediated isothermal amplification), allowing better detection of target mRNA without the need for RNA extraction kits or complex lab steps.

Using Kisspeptin (KiSS1) mRNA as a marker, the team successfully detected placental exosomes with high sensitivity and specificity, confirmed by both RT-qPCR and RT-LAMP. The platform supports dual-mode readout (fluorescent and color-based), making it suitable for both visual and quantitative results. It is also simple, low-cost, and ideal for use in low-resource or remote settings.

This is the first time placental mRNA has been detected using an integrated RT-LAMP approach, offering a more informative alternative to miRNA-based methods. Ongoing clinical validation will further assess its potential as a reliable tool for early risk assessment in maternal healthcare.

Shaon Joins MicroTAS 2025 to Share Maternal Health Diagnostics

Understanding DNA Adsorption on Gold Surfaces: The eMethylsorb Approach

The adsorption of unmodified DNA—meaning DNA without chemical tags like thiol groups—onto bare gold surfaces has traditionally been seen as "non-specific" and "hard to control." However, research showed that this process actually depends on the DNA base composition, following a clear affinity order: adenine (A) > cytosine (C) > guanine (G) > thymine (T).

This understanding opened up a new, reliable way to control how unmodified DNA binds to gold surfaces. Because the binding is strongly dependent on the DNA sequence, it also makes it possible to distinguish between different DNA strands—such as those representing methylated and unmethylated sequences after bisulphite treatment.

Building on this principle, we developed a simple and powerful electrochemical method called eMethylsorb. This technique allows direct detection of DNA methylation by comparing how strongly different DNA samples adsorb to a gold electrode.

How It Works – The eMethylsorb Process
The video below explains the core idea. In brief:

1.	DNA is extracted from cell lines and treated with bisulphite. This treatment changes unmethylated cytosines into uracils, while methylated cytosines remain unchanged.
2.	The samples are then amplified using asymmetric PCR to produce single-stranded DNA (ssDNA). In this process, methylated cytosines are copied into guanines, and uracils into adenines.
3.	These ssDNA amplicons are directly adsorbed onto a gold electrode.
4.	The amount of DNA bound to the gold surface is measured using differential pulse voltammetry (DPV) with the [Fe(CN)₆]³⁻/⁴⁻ redox system.

This label-free, sequence-dependent method provides a fast and cost-effective way to detect DNA methylation, making it ideal for clinical and diagnostic applications.


eMethylsorb Technology for DNA Methylation Using DNA–Gold Affinity Interactions

Surface Plasmon Resonance Version of eMethylsorb Technology

This video explains the basic principle behind the Methylsorb technology, using a Surface Plasmon Resonance (SPR) approach. 

In short, DNA samples extracted from cell lines were first treated with bisulphite. This treatment converts unmethylated cytosines into uracils, while methylated cytosines remain unchanged. The samples were then processed using asymmetric PCR to produce single-stranded DNA (ssDNA). During this step, methylated cytosines are copied into guanines, and uracils into adenines. 

The resulting ssDNA amplicons were then directly adsorbed onto a gold sensor chip. To measure how much DNA was adsorbed, we used SPR biosensing. This technique tracks changes in the refractive index at the chip surface in real time. These changes—seen as shifts in the SPR signal—are directly related to the amount of DNA bound to the surface, enabling accurate, real-time, and label-free detection of target sequences.

Methylsorb Technology for Detecting DNA Methylation Using Gold-DNA Affinity Interaction

We are developing advanced nanoshearing devices that can isolate and detect cancer cells from blood samples with high precision. These devices use a process called nanoshearing, which is driven by alternating current (AC) electrohydrodynamics—a technique that generates fluid movement just nanometers above the electrode surface.

By adjusting the frequency and strength of the AC field, we can fine-tune the system to selectively capture cancer cells that are strongly and specifically bound to the surface, while removing loosely or non-specifically attached cells and other particles.

Using this method, we have successfully built and tested custom microfluidic devices that can detect circulating tumor cells (CTCs) even when present in very low numbers, among millions of normal blood cells. Our results show that this technology offers a powerful and selective approach for early cancer detection and monitoring.

