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Article: Ultrasensitive Label-Free Detection of Unamplified Multidrug-Resistance Bacteria Genes with a Bimodal Waveguide Interferometric Biosensor.

Maldonado, Jesús / González-Guerrero, Ana Belén / Fernández-Gavela, Adrián / González-López, Juan José / Lechuga, Laura M

Diagnostics (Basel, Switzerland)

2020 Volume 10, Issue 10

Abstract: Infections by multidrug-resistant bacteria are becoming a major healthcare emergence with millions of reported cases every year and an increasing incidence of deaths. An advanced diagnostic platform able to directly detect and identify antimicrobial ... ...

Abstract	Infections by multidrug-resistant bacteria are becoming a major healthcare emergence with millions of reported cases every year and an increasing incidence of deaths. An advanced diagnostic platform able to directly detect and identify antimicrobial resistance in a faster way than conventional techniques could help in the adoption of early and accurate therapeutic interventions, limiting the actual negative impact on patient outcomes. With this objective, we have developed a new biosensor methodology using an ultrasensitive nanophotonic bimodal waveguide interferometer (BiMW), which allows a rapid and direct detection, without amplification, of two prevalent and clinically relevant Gram-negative antimicrobial resistance encoding sequences: the extended-spectrum betalactamase-encoding gene
Language	English
Publishing date	2020-10-19
Publishing country	Switzerland
Document type	Journal Article
ZDB-ID	2662336-5
ISSN	2075-4418
ISSN	2075-4418
DOI	10.3390/diagnostics10100845
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Label-free bimodal waveguide immunosensor for rapid diagnosis of bacterial infections in cirrhotic patients.

Maldonado, Jesús / González-Guerrero, Ana Belén / Domínguez, Carlos / Lechuga, Laura M

Biosensors & bioelectronics

2016 Volume 85, Page(s) 310–316

Abstract: Spontaneous bacterial peritonitis is an acute bacterial infection of ascitic fluid; it has a high incidence in cirrhotic patients and it is associated with high mortality. In such a situation, early diagnosis and treatment is crucial for the survival of ... ...

Abstract	Spontaneous bacterial peritonitis is an acute bacterial infection of ascitic fluid; it has a high incidence in cirrhotic patients and it is associated with high mortality. In such a situation, early diagnosis and treatment is crucial for the survival of the patient. However, bacterial analysis in ascitic fluid is currently based on culture methods, which are time-consuming and laborious. We report here the application of a photonic interferometer biosensor based on a bimodal waveguide (BiMW) for the rapid and label-free detection of bacteria directly in ascitic fluid. The device consists of a straight waveguide in which two modes of the same polarization interfere while interacting with the external medium through their evanescent fields. A bimolecular event occurring on the sensor area of the device (e.g. capturing bacteria) will differently affect each light mode, inducing a variation in the phase of the light exiting at the output of the waveguide. In this work, we demonstrate the quantitative detection of Bacillus cereus in buffer medium and Escherichia coli in undiluted ascitic fluid from cirrhotic patients. In the case of Bacillus cereus detection, the device was able to specifically detect bacteria at relevant concentrations in 12.5min and in the case of Escherichia coli detection, the analysis time was 25min. Extrapolation of the data demonstrated that the detection limits of the biosensor could reach few bacteria per milliliter. Based on the results obtained, we consider that the BiMW biosensor is positioned as a promising new clinical tool for user-friendly, cost-effective and real-time microbiological analysis.
MeSH term(s)	Ascitic Fluid/microbiology ; Bacillus cereus/isolation & purification ; Bacteria/isolation & purification ; Bacterial Infections/complications ; Bacterial Infections/diagnosis ; Biosensing Techniques/instrumentation ; Equipment Design ; Escherichia coli/isolation & purification ; Escherichia coli Infections/complications ; Escherichia coli Infections/diagnosis ; Humans ; Immunoassay/instrumentation ; Interferometry/instrumentation ; Limit of Detection ; Liver/microbiology ; Liver Cirrhosis/complications ; Liver Cirrhosis/microbiology
Language	English
Publishing date	2016-11-15
Publishing country	England
Document type	Evaluation Studies ; Journal Article
ZDB-ID	1011023-9
ISSN	1873-4235 ; 0956-5663
ISSN (online)	1873-4235
ISSN	0956-5663
DOI	10.1016/j.bios.2016.04.095
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Article ; Online: Label-free detection of nosocomial bacteria using a nanophotonic interferometric biosensor.

Maldonado, Jesús / Estévez, M-Carmen / Fernández-Gavela, Adrián / González-López, Juan José / González-Guerrero, Ana Belén / Lechuga, Laura M

The Analyst

2019 Volume 145, Issue 2, Page(s) 497–506

Abstract: Nosocomial infections are a major concern at the worldwide level. Early and accurate identification of nosocomial pathogens is crucial to provide timely and adequate treatment. A prompt response also prevents the progression of the infection to life- ... ...

Abstract	Nosocomial infections are a major concern at the worldwide level. Early and accurate identification of nosocomial pathogens is crucial to provide timely and adequate treatment. A prompt response also prevents the progression of the infection to life-threatening conditions, such as septicemia or generalized bloodstream infection. We have implemented two highly sensitive methodologies using an ultrasensitive photonic biosensor based on a bimodal waveguide interferometer (BiMW) for the fast detection of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), two of the most prevalent bacteria associated with nosocomial infections. For that, we have developed a biofunctionalization strategy based on the use of a PEGylated silane (silane-PEG-COOH) which provides a highly resistant and bacteria-repelling surface, which is crucial to specifically detect each bacterium. Two different biosensor assays have been set under standard buffer conditions: one based on a specific direct immunoassay employing polyclonal antibodies for the detection of P. aeruginosa and another one employing aptamers for the direct detection of MRSA. The biosensor immunoassay for P. aeruginosa is fast (it only takes 12 min) and specific and has experimentally detected concentrations down to 800 cfu mL-1 (cfu: colony forming unit). The second one relies on the use of an aptamer that specifically detects penicillin-binding protein 2a (PBP2a), a protein only expressed in the MRSA mutant, providing a photonic biosensor with the ability to identify the resistant pathogen MRSA and differentiate it from methicillin-susceptible S. aureus (MSSA). Direct, label-free, and selective detection of whole MRSA bacteria has been achieved, making possible the direct detection of also 800 cfu mL-1. According to the signal-to-noise (S/N) ratio of the device, a theoretical limit of detection (LOD) of around 49 and 29 cfu mL-1 was estimated for P. aeruginosa and MRSA, respectively. Both results obtained under standard conditions reveal the great potential this interferometric biosensor device has as a versatile and specific tool for bacterial detection and quantification, providing a rapid method for the identification of nosocomial pathogens within the clinical requirements of sensitivity for the diagnosis of infections.
MeSH term(s)	Biosensing Techniques/methods ; Cross Infection/diagnosis ; Cross Infection/microbiology ; Humans ; Interferometry/instrumentation ; Interferometry/methods ; Methicillin-Resistant Staphylococcus aureus/genetics ; Methicillin-Resistant Staphylococcus aureus/isolation & purification ; Staphylococcal Infections/diagnosis ; Staphylococcal Infections/microbiology
Language	English
Publishing date	2019-10-25
Publishing country	England
Document type	Journal Article
ZDB-ID	210747-8
ISSN	1364-5528 ; 0003-2654
ISSN (online)	1364-5528
ISSN	0003-2654
DOI	10.1039/c9an01485c
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Article ; Online: Direct and label-free detection of the human growth hormone in urine by an ultrasensitive bimodal waveguide biosensor.

González-Guerrero, Ana Belén / Maldonado, Jesús / Dante, Stefania / Grajales, Daniel / Lechuga, Laura M

Journal of biophotonics

2016 Volume 10, Issue 1, Page(s) 61–67

Abstract: A label-free interferometric transducer showing a theoretical detection limit for homogeneous sensing of 5 × ... ...

Abstract	A label-free interferometric transducer showing a theoretical detection limit for homogeneous sensing of 5 × 10
MeSH term(s)	Biosensing Techniques ; Human Growth Hormone/urine ; Humans ; Interferometry ; Limit of Detection
Chemical Substances	Human Growth Hormone (12629-01-5)
Language	English
Publishing date	2016-09-27
Publishing country	Germany
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2390063-5
ISSN	1864-0648 ; 1864-063X
ISSN (online)	1864-0648
ISSN	1864-063X
DOI	10.1002/jbio.201600154
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Article ; Online: A comparative study of in-flow and micro-patterning biofunctionalization protocols for nanophotonic silicon-based biosensors.

González-Guerrero, Ana Belén / Alvarez, Mar / García Castaño, Andrés / Domínguez, Carlos / Lechuga, Laura M

Journal of colloid and interface science

2013 Volume 393, Page(s) 402–410

Abstract: Reliable immobilization of bioreceptors over any sensor surface is the most crucial step for achieving high performance, selective and sensitive biosensor devices able to analyze human samples without the need of previous processing. With this aim, we ... ...

Abstract	Reliable immobilization of bioreceptors over any sensor surface is the most crucial step for achieving high performance, selective and sensitive biosensor devices able to analyze human samples without the need of previous processing. With this aim, we have implemented an optimized scheme to covalently biofunctionalize the sensor area of a novel nanophotonic interferometric biosensor. The proposed method is based on the ex-situ silanization of the silicon nitride transducer surface by the use of a carboxyl water soluble silane, the carboxyethylsilanetriol sodium salt (CTES). The use of an organosilane stable in water entails advantages in comparison with usual trialkoxysilanes such as avoiding the generation of organic waste and leading to the assembly of compact monolayers due to the high dielectric constant of water. Additionally, cross-linking is prevented when the conditions (e.g. immersion time, concentration of silane) are optimized. This covalent strategy is followed by the bioreceptor linkage on the sensor area surface using two different approaches: an in-flow patterning and a microcontact printing using a biodeposition system. The performance of the different bioreceptor layers assembled is compared by the real-time and label-free immunosensing of the proteins BSA/mAb BSA, employed as a model molecular pair. Although the results demonstrated that both strategies provide the biosensor with a stable biological interface, the performance of the bioreceptor layer assembled by microcontact printing slightly improves the biosensing capabilities of the photonic biosensor.
MeSH term(s)	Biosensing Techniques/instrumentation ; Nanostructures/chemistry ; Optical Devices ; Silicon/chemistry
Chemical Substances	Silicon (Z4152N8IUI)
Language	English
Publishing date	2013-03-01
Publishing country	United States
Document type	Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	241597-5
ISSN	1095-7103 ; 0021-9797
ISSN (online)	1095-7103
ISSN	0021-9797
DOI	10.1016/j.jcis.2012.10.040
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Article ; Online: All-optical phase modulation for integrated interferometric biosensors.

Dante, Stefania / Duval, Daphné / Sepúlveda, Borja / González-Guerrero, Ana Belen / Sendra, José Ramón / Lechuga, Laura M

Optics express

2012 Volume 20, Issue 7, Page(s) 7195–7205

Abstract: We present the theoretical and the experimental implementation of an all-optical phase modulation system in integrated Mach-Zehnder Interferometers to solve the drawbacks related to the periodic nature of the interferometric signal. Sensor phase is tuned ...

Abstract	We present the theoretical and the experimental implementation of an all-optical phase modulation system in integrated Mach-Zehnder Interferometers to solve the drawbacks related to the periodic nature of the interferometric signal. Sensor phase is tuned by modulating the emission wavelength of low-cost commercial laser diodes by changing their output power. FFT deconvolution of the signal allows for direct phase readout, immune to sensitivity variations and to light intensity fluctuations. This simple phase modulation scheme increases the signal-to-noise ratio of the measurements in one order of magnitude, rendering in a sensor with a detection limit of 1.9·10⁻⁷ RIU. The viability of the all-optical modulation approach is demonstrated with an immunoassay detection as a biosensing proof of concept.
MeSH term(s)	Biosensing Techniques/instrumentation ; Equipment Design ; Equipment Failure Analysis ; Immunoassay/instrumentation ; Interferometry/instrumentation ; Systems Integration
Language	English
Publishing date	2012-03-26
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	1491859-6
ISSN	1094-4087 ; 1094-4087
ISSN (online)	1094-4087
ISSN	1094-4087
DOI	10.1364/OE.20.007195
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Nanophotonic lab-on-a-chip platforms including novel bimodal interferometers, microfluidics and grating couplers.

Duval, Daphné / González-Guerrero, Ana Belén / Dante, Stefania / Osmond, Johann / Monge, Rosa / Fernández, Luis J / Zinoviev, Kirill E / Domínguez, Carlos / Lechuga, Laura M

Lab on a chip

2012 Volume 12, Issue 11, Page(s) 1987–1994

Abstract: One of the main limitations for achieving truly lab-on-a-chip (LOC) devices for point-of-care diagnosis is the incorporation of the "on-chip" detection. Indeed, most of the state-of-the-art LOC devices usually require complex read-out instrumentation, ... ...

Abstract	One of the main limitations for achieving truly lab-on-a-chip (LOC) devices for point-of-care diagnosis is the incorporation of the "on-chip" detection. Indeed, most of the state-of-the-art LOC devices usually require complex read-out instrumentation, losing the main advantages of portability and simplicity. In this context, we present our last advances towards the achievement of a portable and label-free LOC platform with highly sensitive "on-chip" detection by using nanophotonic biosensors. Bimodal waveguide interferometers fabricated by standard silicon processes have been integrated with sub-micronic grating couplers for efficient light in-coupling, showing a phase resolution of 6.6 × 10(-4)× 2π rad and a limit of detection of 3.3 × 10(-7) refractive index unit (RIU) in bulk. A 3D network of SU-8 polymer microfluidics monolithically assembled at the wafer-level was included, ensuring perfect sealing and compact packaging. To overcome some of the drawbacks inherent to interferometric read-outs, a novel all-optical wavelength modulation system has been implemented, providing a linear response and a direct read-out of the phase variation. Sensitivity, specificity and reproducibility of the wavelength modulated BiMW sensor has been demonstrated through the label-free immunodetection of the human hormone hTSH at picomolar level using a reliable biofunctionalization process.
MeSH term(s)	Antibodies/immunology ; Biosensing Techniques ; Humans ; Interferometry/instrumentation ; Interferometry/methods ; Lab-On-A-Chip Devices ; Microfluidic Analytical Techniques/instrumentation ; Microfluidic Analytical Techniques/methods ; Nanotechnology/instrumentation ; Nanotechnology/methods ; Optics and Photonics/instrumentation ; Optics and Photonics/methods ; Refractometry ; Thyrotropin/analysis ; Thyrotropin/immunology
Chemical Substances	Antibodies ; Thyrotropin (9002-71-5)
Language	English
Publishing date	2012-05-08
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2056646-3
ISSN	1473-0189 ; 1473-0197
ISSN (online)	1473-0189
ISSN	1473-0197
DOI	10.1039/c2lc40054e
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article: comparative study of in-flow and micro-patterning biofunctionalization protocols for nanophotonic silicon-based biosensors

González-Guerrero, Ana Belén / Alvarez, Mar / Castaño, Andrés García / Domínguez, Carlos / Lechuga, Laura M.

Journal of colloid and interface science

Volume v. 393

Abstract	Reliable immobilization of bioreceptors over any sensor surface is the most crucial step for achieving high performance, selective and sensitive biosensor devices able to analyze human samples without the need of previous processing. With this aim, we have implemented an optimized scheme to covalently biofunctionalize the sensor area of a novel nanophotonic interferometric biosensor. The proposed method is based on the ex-situ silanization of the silicon nitride transducer surface by the use of a carboxyl water soluble silane, the carboxyethylsilanetriol sodium salt (CTES). The use of an organosilane stable in water entails advantages in comparison with usual trialkoxysilanes such as avoiding the generation of organic waste and leading to the assembly of compact monolayers due to the high dielectric constant of water. Additionally, cross-linking is prevented when the conditions (e.g. immersion time, concentration of silane) are optimized. This covalent strategy is followed by the bioreceptor linkage on the sensor area surface using two different approaches: an in-flow patterning and a microcontact printing using a biodeposition system. The performance of the different bioreceptor layers assembled is compared by the real-time and label-free immunosensing of the proteins BSA/mAb BSA, employed as a model molecular pair. Although the results demonstrated that both strategies provide the biosensor with a stable biological interface, the performance of the bioreceptor layer assembled by microcontact printing slightly improves the biosensing capabilities of the photonic biosensor.
Keywords	biosensors ; silicon nitride ; organic wastes ; crosslinking ; humans ; sodium ; proteins ; surface area
Language	English
Document type	Article
ISSN	0021-9797
Database	AGRIS - International Information System for the Agricultural Sciences and Technology

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