CONTENTS INTRODUCTION COMPONENTS OF BIOSENSORS NANOBIOSENSORS TYPES OF NANOSENSORS AND THEIR APPLICATIONS ENVIRONMENTAL APPLICATIONS FUTURE APPLICATION FUTURE CHALLENGES CONCLUSION

INTRODUCTION Biosensor is generally defined as a measurement system that consist of a probe with a sensitive biological recognition element or bioreceptor,a physicochemical detector component and a transducer in between

THREE COMPONENT OF BIOSENSORS  BIORECEPTORS  TRANSDUCERS  DETECTORS  BIORECEPTORS :-It is a sensitive biological element the interaction of analyte e.g a particular chemical component virus or microorganism with a bioreceptor is designed to generate an effect picked by a transducer which convert the information into measurable effect by the detector for instant an electric signal.

TRANSDUCER:- transduction can accomplished by optical electrochemical and mass detection methods DETECTORS: PRINCIPLE OF DETECTION  Light intensity  heat  Electrochemical  calorimetric  Piezoelectric  optical

NANOBIOSENSORS Nanobiosensor or nanosensors is a biosensor that has dimensions on nanometer size scale. Nanosensors could provide the tools to investigate important biological processes at the cellular level in vivo. The three types of nanosensors with medical application possibilities are

TYPES OF NANOBIOSENSORS CANTILEVER ARRAY SENSOR NANOTUBE SENSOR NANOBIOSENSORS CANTILEVER SENSORS:- Micro fabricated cantilever array sensors are used as ultra sensitive mechanical sensors converting biochemical or physical processes into are recordable signal in micro electromechanical system or nano electromechanical system.

CANTILEVER SENSORS FOR DIAGNOSIS OF DIABETIES MILLITUS Medical application of cantilever based biosensors have been proposed for early diagnosis of diabetes mellitus and can improve the blood glucose monitoring using small or ultra sensitive analytical platforms. CANTILEVER SENSORS FOR BACTERIA FUNGI VIRUSES:-  The devices has also been developed to detect bacteria fungal spore and viruses

 The interaction between specific antibodies for instance antibodies to E.coli immobalised on surface of cantilever and antigens on cell membrane surface results in additional mass loading detected by the device CANTILEVER SENSORS FOR CANCER DIAGNOSIS cantilever arrays can aid cancer diagnosis and can be engineered to bind to molecules associated with cancer such as DNA sequence snp and proteins.

NANOTUBE SENSORS Nano sized carbon tubes coated with strands of DNA can create tiny sensors with abilities to detect odors and tastes these nanosensors could detect molecules on the order of 1 ppm. The researchers tested the nanobiosensors on five different odorants,including methanol and dinitrotoluene, a common chemical that is also frequently a component of military –grade explosives. The nano biosensors could sniff molecules out of the air or taste them in the liquid suggesting applications ranging from domestic security to medical detectors.

APLICATIONS OF NANOTUBE BIOSENSORS NANOTUBES BASED SENSORS BLOOD GLUCOSE MONITORING:- carbon nanotubes are promising sensing candidates to monitor glucose in blood and urine NANOTUBES BASED SENSORS FOR DNA DETECTION:- MWCNT based nano electrode arrays embedded in silicon oxide matrices have been integrated into a electrochemical system for ultra sensitive and rapid DNA detection.

NANOTUBES BASED SENSORS FOR CAPNOGRAPHY carbon nanotubes based chemical gas sensors have great potential in medical applications it is the measurement of carbon dioxide concentration in human respiration and is a indicator of patient status during administration of anesthesia

NANOWIRE BASED SENSORS It is a hybrid of two molecules that are extremely sensitive to out side signals ssDNA which serves as a detector and a carbon nanotubes which functions as transmitter  By putting the two together and they become an extremely versatile type of sensor,capable of finding tiny amount of a specific molecule.

APPLICATIONS OF NANO WIRE BASED ELECTRICAL DETECTION OF SINGLE VIRUS :- Semi conducting silicon nanowires can be configured as field effect transistors for the electrical detection of virus in solution APPLICATIONS OF NANO WIRE BASED ELECTRICAL DETECTION OF BIOMOLECULES:- silicon nanowire field effect transistors devices have been used for detection of small molecule inhibitors of ATP binding to Abl which is a protein kinase whose activity is responsible for chronic myelogenous leukemia.

NANODETECTORS Nano array based bio detection nano array occupied a surface area thousands of time smaller than a standard microarray and therefore present many novel applications APPLICATIONS OFNANOARRAY BASED DETECTORS ULTRA SENSITIVE VIRUS DETECTION :-Virus in human blood sample such as HIV1 can be detected using nano scale antibody based devices ULTRASENSITIVE DETECTION OF PATHOGENIC BIOMARKERS:- One of the major drawback of conventional protein antigen detection methods is the relative insensitivity of the target..

Ultra sensitive tests are need for patient screening and diagnosis in early stage of diseases ULTRASENSITIVE DETECTION OF SINGLE BACTERIA dye/doped silica nanoparticles have been used to develop an assay tool for insitu pathogen quantification in water samples enabling the detection of one bacterial cell.

ENVIRONMENTAL APPLICATIONS DETECTION OF ENVIRONMENTAL POLLUTION AGRICULTURE MONITORING GROUND WATER SCREENING OCEAN MONITORING

FUTURE APPLICATIONS CANCER MONITORING NANOBIOSENSORS PLAY VERY IMPORTANT ROLE IN EARLY CANER DETECTION IN BODY FLUIDS. THE SENSOR IS COATED WITH A CANCER SPECIFIC ANTIBODY OR OTHER MORE RECOGNITION LIGANDS. The capture of a cancer cell or a target protein yields electrical optical or mechanical signal for detection

Identification of biomarkers ↓ Validation of cancer biomarkers ↓ Cancer biomarkers ↓ Ligands probe development ↓ Cancer diagnostic biosensors ← detector ↓ Point of cancer care diagnosis ↓

FUTURE CHALLENGES CURRENT DEVELOPMENT IN CANTILEVER ARRAY SENSORS ARE TOWARS THE IMPROVEMENT OF MEDICAL DIAGNOSTIC TOOLS. EXAMPLES New ways to characterized solutions small amounts of blood or body fluid samples on the other hand from the scientific point of view the challenge lies in optimizing cantilever sensors to improve the sensitivity until the ultimate limit is reached which may be nano mechanical detection of individual molecules.

CONCLUSIONS Nanotechnology offers important new tools expected to have a great impact on many areas in medical technology it provide extraordinary opportunities not only to improve materials and medical devices but also to create new small devices and technologies where existing and more conventional technologies may be reaching their limits.