WS2 Microengineering Taking laboratory diagnosis into the field - - PowerPoint PPT Presentation

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WS2 Microengineering

Taking laboratory diagnosis into the field

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The team

Professor Wamadeva Balachandran (Bala) Principal Investigator

Dr Jeremy Ahern Microfabrication Dr Nada Manivannan Multiphysics Modelling Professor Chris Hudson Electronic Engineering Professor Rob Evans Biosciences Dr Predraig Slijpevic Biosciences Pascal Craw PhD Student Biomedical Engineering Branavan Nehru PhD Student Paper microfluidics Dr Yanmeng Xu Printed Electronics Sara Chaychian PhD Student Electrical Engineering Tosan Ereku PhD Student Engineering Design Dr Krishna Burugapalli Biomedical Engineering Shavini Wijesuriya PhD Student Engineering Design Sana Hussain Visiting Scholar Biosciences Sivanesan Tulasidas PhD Student Wireless Communication Dr Ruth Mackay BioMEMS/NEMS

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• Lab-on-chip for POCT concept
• Patient sample collection
• Microfluidics
• DNA extraction
• Isothermal amplification
• Nucleic acid detection
• Electronic control and communication
• Instrumentation design
• Paper-based microfluidics
• Future research

WS2 Microengineering

Balachandran Lab, Brunel University

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Wireless Interface

DNA Extraction & Purification

Sample collection

MicroFluidic Network DNA Detection Electronic Control System

Integrated Lab-On-a-Chip for POCT Integrated Lab-On-a-Chip for POCT

DNA Amplification Sample concentration & cell lysis

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Modular Research Platform

Electromagnets

Lysis Amplification Detection Sample & Reagents Waste

Disposable Cartridge

GPS RFID Bluetooth

3G Mobile

USB WiFi

Microcontroller Power Management

Display and User Interface

Magnetic Electrochemical Optical

SPR

MEMS Nanowire

Nucleic Acid Detector Pumps Valve actuators Thermal control

Standardisation Concentration / Purification

Sample pre-treatment

Electronic System

Control System Communication

Interface Interface

Valves Sensors Electromagnets

Microfluidic Network

Pathways

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Sample Collection

• Swab and urine
• 4mL of urine
• 100uL swab elute
• Simple design ‘Fool-proof’
• Direct integration to

extraction device

• Integrated lysis

Urine collection devices

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Finite element analysis to inform design

Streamline depiction of flow from inlets to device discharge orifice Cessational flow of urine from six inlets into the air-filled cavity

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Deformable silicone reservoirs Cam actuated pump filling microfluidic chip 25uL microfluidic chip

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DNA extraction

• Novel membrane in development
• Cationic bioploymer membrane

Reduces number of steps for DNA extraction

• No chaotropic reagents
• Simple pH (5-9) change in aqueous

solutions

• 2 reagents required
• Simple flow over device: no

centrifugation/active mixing

Two DNA extraction devices with embedded biopolymer membrane

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DNA Extraction performance

10 20 30 40 50 60 70 80 90 100 0.1 100

Percentage Recovery (%) Sample Concentration (ng/uL)

Spin Column (Qiagen) Bioplymer membrane

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1 2 3 4 5 6 7 8 9 10

25µL tube reaction 25µL On-chip reaction Final DNA concentration (ug/mL)

On-chip helicase dependent amplification

Isothermal Amplification

• Helicase dependent amplification
• Single temperature (65⁰C)
• 109 amplification power
• < 20minutes reaction time
• Can be used with real-time

fluorescence chemistries

Real-time plot of HDA reaction

Fluorescence

Time (minutes)

0 5 10 15 20 25 30 35 40

Negative control Positive Control

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On-chip amplification and detection

Fluorescence detection on microfluidic chip

490nm LED Amplified Photodiode Emission band-pass Filter (530nm) Optical Fibre 3mm PMMA Reaction Chamber PMMA Fluidic Chip

Finite element analysis of microfluidic chip to characterise thermal properties 25µL microfluidic chip

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Planar Spiral Inductor for Inductance-based biosensor

Magnetic bead-based DNA Detection

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Planar Inductor Simulation, Magnetic Flux Density = 4 - 16 mT Simple circuitry to allow detection of magnetic beads

Magnetic bead-based DNA Detection

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Brass/Al mould for a detection microfluidic device Detection device with automated fluid flow and electrodes Al mould for a fully integrated microfluidic system Integrated microfluidic PDMS device

10mm 10mm

10mm

Integrated microfluidic cartridges

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Communication Design Strategy Communication Design Strategy Communication Design Strategy Communication Design Strategy

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Paper based microfluidics (µPADs) Paper based microfluidics (µPADs) Paper based microfluidics (µPADs) Paper based microfluidics (µPADs)

Fabrication of µPADs Fabrication of µPADs Fabrication of µPADs Fabrication of µPADs

Wax penetration: comparison of printed barriers before and after curing at 120oC for 15 minutes

Printed barriers of 500 µm produced fully functional barriers. A minimum channel width of ~ 300 µm is achievable. Printed barriers (Wax) Cured barriers (Wax) Xerox ColorQubeTM 8570N solid ink Printer Multiplexing: A single sample effectively delivered into 5 test zones DNA mobility on a µPAD Inkjet printed silver electrodes (25 µm)

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DNA detection on µPADs DNA detection on µPADs DNA detection on µPADs DNA detection on µPADs

0 s 30 s 90 s W 1 W 2

0s – Blank 30s – 20uL FITC tagged 25mer DNA sample advancing (0.01nM). 90s – Further movement of the sample into the waste zone. W1 – DNA sample getting washed away by water into the waste zone. W2 – Further washing of the DNA by water into the waste zone.

Water as control Blank paper as control Serially diluted 0.1pM DNA Serially diluted 1pM DNA Serially diluted 0.01nM DNA Stock DNA solution 0.1nM

All above pictures are obtained through the BIO-RAD Gel DOCTM XR+ system and the associated image analysis software Image LabTM.

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Handheld device development

Future GUI

Current handheld platform in development