Carbon Nanotube Ink Research Articles

A Breathable and Strain‐Insensitive Multi‐Layered E‐Skin Patch for Digital Healthcare Wearables

AbstractIn this study, a breathable and strain‐insensitive multi‐layered electronic skin (e‐skin) capable of real‐time detection and distinction of electrocardiogram (ECG) signals, temperature, and skin hydration is developed. Leveraging a scalable benchtop method, sensing elements are transferred onto porous and hydrophobic substrates, followed by multi‐layer stacking to enable multimodal sensing. The sensing elements, a combination of carbon nanotube and nanoporous carbon (CNT@NPC) ink, are applied using strain‐insensitive patterned masks, then spray‐coated with styrene–ethylene–butylene–styrene (SEBS) to create a hierarchical porous network through phase separation. The CNT@NPC networks exhibit an improvement in strain insensitivity with active sensing capabilities due to their adaptable molecular tuning capacity and exceptional electrical conductivity. The porous SEBS substrate offers strong bonding with CNT@NPC attributed to the π–π interactions and high kinetic energy dispersion from spray coating allowing effective transfer. This unique design facilitates breathability, and miniaturization that minimizes the interference between different sensing modalities, ensuring accurate and reliable data acquisition. The breathability (3.49 mg cm−2 h−1) and the non‐smearing nature of the multi‐layered e‐skin enables simultaneous monitoring of temperature (0.198% °C−1), skin hydration (relative humidity = 0.77% %−1), and ECG (26 ± 1 dB) with continuous data transmission to a remote smartphone interface.

A super-elastic wearable strain sensor based on PU/CNTs yarns for human-motion detection

Yarn-based strain sensors increasingly garner attention for their potential applications in intelligent wearable electronic devices. Developing highly elastic conductive composite yarns and integrating them into fabrics poses a significant challenge in manufacturing flexible electronic devices. In this study, a polyurethane (PU)/carbon nanotubes (CNTs) composite nanofiber yarn was successfully and continuously prepared using a simple conjugate spinning technique. The resulting yarn exhibited excellent mechanical properties, with a high tensile strength of up to 56.7 MPa and an elongation at break of 504 %. A yarn with a dual conductive network was created using CNTs ink dip-coating. It demonstrated excellent conductivity (8.77 S/cm), exceptional linear variation, and reusability. The sensor remained stable after 1000 cycles of testing, exhibiting a relative electrical resistance change of up to 594 % under a strain of 350 %. Additionally, taking advantage of the inherent knittability of one-dimensional yarn structures, a susceptible wearable textile-type strain sensor was successfully developed using textile knitting technology. This sensor can be directly attached to the surface of the human body for real-time monitoring of human body dynamics. This sensor showcases significant promise for use in flexible, intelligent, wearable electronic devices.

3D-Printed Soft Temperature Sensors Based on Thermoelectric Effects for Fast Mapping of Localized Temperature Distributions.

We propose a novel design of thermoelectric (TE) effect-based soft temperature sensors for directly monitoring localized subtle temperature stimuli. This design integrates rheology-engineered three-dimensional (3D) printing of high-performance carbon-based TE materials and polymer-based viscoelastic materials with low thermal conductivity. Rheological engineering of carbon nanotube (CNT) TE inks ensures the 3D printing of highly sensitive TE sensing units on directly written 3D soft platforms. Additionally, we pre-dope CNT inks with p- and n-type organic dopants to achieve high sensitivity and a fast response to temperature changes. The introduced 3D soft platforms with low thermal conductivity lead to an efficient thermal gradient on TE sensing units in the out-of-plane direction. Furthermore, encapsulating the temperature sensor array with the same polymer-based materials as the 3D soft platforms facilitates independent detection of localized temperature stimuli by minimizing thermal interaction between sensing units, resulting in precise temperature mapping by localized detection. Our 3D-printed soft temperature sensors exhibit high sensitivity to relatively small temperature changes, with a minimum sensing resolution of 0.1 K within tens of milliseconds. Moreover, the temperature sensor array not only detects localized temperature stimuli by imaging the temperature distribution but also demonstrates remarkable mechanical reliability against repetitive deformation with high accuracy.

Fabrication of highly conductive polyester fabrics using single-wall carbon nanotubes inks for EMI shielding

Abstract We have fabricated single-wall carbon nanotube (SWCNT)-coated electrically conductive polyester fabric using a low-temperature (LT) dip-and-dry method. Polyester fibers are suitable for industrial applications because of their higher heat resistance. We focused on the surface modification of polyester fibers using N,N-dimethyl-formamide solvent and then improved the adhesion of the SWCNT to polyester fibers. The low sheet resistance of 4.3 ± 0.3 Ω sq−1 was achieved while maintaining the intrinsic flexibility and durability of polyester fabrics by using the LT dip-and-dry method. Moreover, we demonstrated the electromagnetic interference (EMI) shielding using the fabricated electrically conductive polyester fabric. The EMI shielding effectiveness (SE) was measured in the frequency ranges of 8–12 GHz using waveguides and a vector network analyzer. The measured SE of the fabricated electrically conductive polyester fabric was about −34 dB and fulfilled the requirement for practical EMI shielding.

Nozzle-Free Printing of CNT Electronics Using Laser-Generated Focused Ultrasound.

Printed electronics have made remarkable progress in recent years and inkjet printing (IJP) has emerged as one of the leading methods for fabricating printed electronic devices. However, challenges such as nozzle clogging, and strict ink formulation constraints have limited their widespread use. To address this issue, a novel nozzle-free printing technology is explored, which is enabled by laser-generated focused ultrasound, as a potential alternative printing modality called Shock-wave Jet Printing (SJP). Specifically, the performance of SJP-printed and IJP-printed bottom-gated carbon nanotube (CNT) thin film transistors (TFTs) is compared. While IJP required ten print passes to achieve fully functional devices with channel dimensions ranging from tens to hundreds of micrometers, SJP achieved comparable performance with just a single pass. For optimized devices, SJP demonstrated six times higher maximum mobility than IJP-printed devices. Furthermore, the advantages of nozzle-free printing are evident, as SJP successfully printed stored and unsonicated inks, delivering moderate electrical performance, whereas IJP suffered from nozzle clogging due to CNT agglomeration. Moreover, SJP can print significantly longer CNTs, spanning the entire range of tube lengths of commercially available CNT ink. The findings from this study contribute to the advancement of nanomaterial printing, ink formulation, and the development of cost-effective printable electronics.

Upscaling Thermoelectrics: Micron-Thick, Half-a-Meter-Long Carbon Nanotube Films with Monolithic Integration of p- and n-Legs.

In order for organic thermoelectrics to successfully establish their own niche as energy-harvesting materials, they must reach several crucial milestones, including high performance, long-term stability, and scalability. Performance and stability are currently being actively studied, whereas demonstrations of large-scale compatibility are far more limited and for carbon nanotubes (CNTs) are still missing. The scalability challenge includes material-related economic considerations as well as the availability of fast deposition methods that produce large-scale films that simultaneously satisfy the thickness constraints required for thermoelectric modules. Here we report on true solutions of CNTs that form gels upon air exposure, which can then be dried into micron-thick films. The CNT ink can be extruded using a slot-shaped nozzle into a continuous film (more than half a meter in the present paper) and patterned into alternating n- and p-type components, which are then folded to obtain the finished thermoelectric module. Starting from a given n-type film, differentiation between the n and p components is achieved by a simple postprocessing step that involves a partial oxidation reaction and neutralization of the dopant. The presented method allows the thermoelectric legs to seamlessly interconnect along the continuous film, thus avoiding the need for metal electrodes, and, most importantly, it is compatible with large-scale printing processes. The resulting thermoelectric legs retain 80% of their power factor after 100 days in air and about 30% after 300 days. Using the proposed methodology, we fabricate two thermoelectric modules of 4 and 10 legs that can produce maximum power outputs of 1 and 2.4 μW, respectively, at a temperature difference ΔT of 46 K.

Highly aligned electrospun film with wave-like structure for multidirectional strain and visual sensing

Recently, flexible strain sensors have attracted great attention on account of the application potential in medical treatment, flexible prosthetics and human–machine interaction. Nevertheless, traditional uniaxial strain sensors cannot detect movement in different directions, limiting the applications in sensing technologies. In addition, it is still a significant challenge to simultaneously acquire visualized and high-performance strain sensors. Here, a highly flexible sensor with visual sensing function was fabricated by spraying silver nanowires (AgNWs)/carbon nanotubes (CNTs) ink on the aligned thermoplastic polyurethane (TPU) electrospun mat. The sensing performances of AgNWs/CNTs aligned TPU fluorescent mats (ACUM-F) are individually explored in vertical and parallel directions. Herein, the ACUM-F in vertical can exhibit high sensitivity (gauge factor (GF) up to 244.3), wide working range (0.1 ∼ 380 % strain), fast response/recovery time (80 ms/80 ms), good sensing durability and reproducibility (1000 stretching/releasing test cycles). Furthermore, ACUM-F is assembled as strain sensors to monitor various human body movements, which can achieve sign language interpretation through finger gesture monitoring, demonstrating its great potential in human–machine interaction. The direction-aware application of novel multidirectional sensors with visual sensing functions may bring inspiration for a new era of flexible electronics development.

Patterned Coating of Ionic Diode Arrays Toward Flexible Moist‐Electric Generators to Power Wireless Sensor Nodes

AbstractUbiquitous moisture is attractive for developing sustainable mobile power sources. However, how to endow moisture‐electric generators (MEGs) with fine design, mass customization, high power output, and foldability is still a largely unsolved problem. In this work, based on the Patterned Coating method, use is made of modulated carbon nanotube, nano‐Al2O3, and liquid metal inks to design and fabricate MEGs with properties required for their applications. A single MEG of the ionic diode type thus fabricated can generate an open‐circuit voltage (VOC) of 1.03 V and a short‐circuit current density (JSC) of 47.77 µA cm−2. Through large‐area integrated fabrication, an array containing 160 MEGs can generate a VOC of 154.1 V, and an array containing 100 MEGs can produce a short‐circuit current of 1.95 mA. In addition, the excellent wearability of MEG is verified by analyzing its electrical output performance after subjecting it to 800 cycles of bending deformations. The simple and cost‐saving fabrication technology issued from the work opens new perspectives for MEG applications and paves a path to their industrialization. For example, the customizable ionic diode arrays can meet the on‐demand power supply requirements of wireless sensor network nodes in the Internet of Things.

Paper-Based Analytical Device Based on Potentiometric Transduction for Sensitive Determination of Phenobarbital.

In medicine, barbiturates are a class of depressive medications used as hypnotics, anticonvulsants, and anxiolytics. For the treatment of specific forms of epilepsy and seizures in young children in underdeveloped countries, the World Health Organization recommends phenobarbital (PBAR), a barbiturate drug. This review describes the fabrication and characterization of a paper-based analytical apparatus for phenobarbital detection that is straightforward, affordable, portable, and disposable. All of the solid-state ion-selective electrodes (ISEs) for PBAR as well as a Ag/AgCl reference electrode were constructed and optimized on a nonconductive paper substrate. Using carbon nanotube ink, the sensors were made to function as an ion-to-electron transducer and to make the paper conductive. A suitable polymeric membrane is drop-cast onto the surface of the carbon ink orifice. The pyrido-tetrapeptide and pyrido-hexapeptide derivatives, which were recently synthesized, functioned as distinct ionophores in the PBAR-membrane sensor, enabling its detection. With a detection limit of 5.0 × 10-7 M, the manufactured analytical device demonstrated a Nernstian response to PBAR anions in 50 mM phosphate buffer, pH 8.5, over a linear range of 1.0 × 10-6 to 1.0 × 10-3 M. The PBAR-based sensors showed quick (less than 5 s) response times for PBAR ion detection. The modified separate solution method was utilized to evaluate the selectivity pattern of these novel ionophores with respect to PBAR ions in comparison to other common anions. The analytical instrument that was exhibited on paper had good precision both within and between days. The suggested technology assisted in the detection of trace amounts of PBAR in real pharmaceutical samples. A comparison was made between the data acquired using the HPLC reference method and the information obtained by the recommended potentiometric approach. The described paper-based analytical device may be a good choice for point-of-care PBAR determination because it is cheap and easy to find and can self-pump (especially when combined with potentiometric detection).

The influence of electrode geometry on the electrochemical performance of fabric-based screen-printed coplanar supercapacitors

Coplanar supercapacitors are promising flexible energy storage systems due to the excellent flexibility and tailored shapes and sizes of electrodes. However, the influence mechanism of electrode’ geometry parameter on the electrochemical performance of the flexible coplanar supercapacitors needs to be elucidated to realize the performance enhancement. Herein, the flexible coplanar supercapacitors with different thicknesses, widths and lengths of screen-printed electrodes were constructed on the cotton fabric substrates utilizing multi-walled carbon nanotubes ink and polymer gel electrolytes. The relationship between electrodes' geometry and overall electrochemical performance of flexible coplanar supercapacitors was detailed analyzed and demonstrated by employing equivalent series circuit model and electrode kinetic theory. Furthermore, due to the favorable aspect ratio and relatively low electrode and electrolyte resistance, the fabric-based coplanar supercapacitor with electrode size of 4 × 10 mm shows optimal electrochemical performance with areal capacitance of 3.08 mF cm−2 at 20 mV s−1, fast electrode response and effective kinetic process. Most importantly, the fabric-based supercapacitor exhibits excellent flexibility and cycling performance with capacitance retention rate over 79.6 % after 4000 charge and discharge cycles, indicating application potential in wearable electronic devices. The analysis and assessments of electrodes' geometry provides theoretical reference for the electrode design and optimization of flexible coplanar supercapacitors.

Fully Printed Low-Voltage Field-Effect Transistor Biosensor Array for One-Drop Detection of Shewanella onedensis MR-1 Bacteria

Fast and simple bacterial detection using an in situ measurement technique is indispensable for medical diagnosis, public hygiene, and environmental monitoring. However, current bacterial detection techniques still require large measurement apparatus with complicated analysis. In this work, we propose the use of a full printing process for the fabrication of field-effect-transistor (FET) biosensors using π-junction gold nanoparticle (AuNP) ink and semiconducting single-wall carbon nanotube (sc-SWCNT) ink, which show a low voltage (<1 V) and high field-effect mobility (70 cm2 V–1 s–1), allowing for highly efficient and accurate bacterial detection from a minimal size of the target analyte droplet. This method provides a fully printed sensing platform for the determination of Shewanella onedensis MR-1 bacteria with a linear range of 10–1000 CFU in one drop of bacterial suspension (0.1 μL) (i.e., 105 to 107 CFU/mL), which is promising for the practical application of low-cost and disposable biosensors, especially in the regions with restricted medical conditions.

Development of a facile aerogel‐based ion‐selective electrode using cellulose and carbon nanotubes as transducer materials for potentiometric application

AbstractFacile, lightweight, and sustainable aerogels have been a growing interest in their applications as support matrixes in the current environmental and energy challenges. In this study, a cellulose aerogel (CA) is fabricated using a homogeneous dispersion of cellulose fibers in an alkali‐urea aqueous solution and a carbon nanotube ink (CNT‐ink) to increase its electrical and conductive behavior in a potentiometric analysis. The physicochemical and morphological properties of the resultant composite aerogels (CA, CA1, and CA2) are investigated by thermal, water resistance, mechanical, FTIR, and SEM analysis. The prepared material exhibits a structured solid network that is visualized through SEM in which fibers are functionalized with CNTs. The results from compressive tests reveal that CA2 has excellent mechanical properties. A saturated CA with CNT‐ink can turn on a white LED and potentiometric measurements by preparing an aerogel‐based ion‐selective electrode (CA2 ‐ ISE) with a potassium ion‐selective membrane (K+ − ISM) reveal good sensitivity at room temperature for the detection in a specific electrolyte solution.

A hybrid multi-objective optimization of functional ink composition for aerosol jet 3D printing via mixture design and response surface methodology

The limited electrical performance of microelectronic devices caused by low inter-particle connectivity and inferior printing quality is still the greatest hurdle to overcome for Aerosol jet printing (AJP) technology. Despite the incorporation of carbon nanotubes (CNTs) and specified solvents into functional inks can improve inter-particle connectivity and ink printability respectively, it is still challenging to consider multiple conflicting properties in mixture design simultaneously. This research proposes a novel hybrid multi-objective optimization method to determine the optimal functional ink composition to achieve low electrical resistivity and high printed line quality. In the proposed approach, silver ink, CNTs ink and ethanol are blended according to mixture design, and two response surface models (ReSMs) are developed based on the Analysis of Variance. Then a desirability function method is employed to identify a 2D optimal operating material window to balance the conflicting responses. Following that, the conflicting objectives are optimized in a more robust manner in the 3D mixture design space through the integration of a non-dominated sorting genetic algorithm III (NSGA-III) with the developed ReSMs and the corresponding statistical uncertainty. Experiments are conducted to validate the effectiveness of the proposed approach, which extends the methodology of designing materials with multi-component and multi-property in AJP technology.

A trimodal detection paper chip for undisclosed drug "sibutramine" in nutraceuticals.

Nutraceuticals are promoted and marketed with the stated label of being natural as well as safe herbal products. In order to enhance their effectiveness, nutraceuticals are usually adulterated with undeclared constituents. Slimming herbs may contain sibutramine (SBT) which is an FDA-banned ingredient due to its fatal outcomes. This current work's aim is to design a trimodal sensor for SBT detection in different herbal slimming formulations. Screen-printed silver and multi-walled carbon nanotube inks were employed for the potentiometric sensor. The sensor was designed to fill a reaction well in which a carbon dot-silver nanoparticle pair was applied for fluorimetric and colorimetric purposes. The trimodal sensor was designed to fit an 8 mm 2-pin LED strip connector. Potentiometric measurement took place upon application of one sample aliquot then the optical reaction proceeded next in a specified zone for optical detection. These multiple detection mechanisms achieved the required selectivity for SBT determination in the presence of other slimming products' additives. This trimodal sensor satisfied World Health Organization standards for point-of-care devices demonstrating the suggested device as a dynamic part for rapid on-site detection of undisclosed SBT.

Scalable self-integrated all-in-one fabric-based supercapacitors with simultaneous enhancement of output voltage and capacitance

All-in-one supercapacitors show broader application prospect in the field of flexible electronics due to the electrochemical stability and durability. Nonetheless, how to simultaneously enhance the output voltage and capacitance of integrated devices while maintain excellent flexibility and reasonable dimension is a critical challenge for the further development and application of all-in-one supercapacitor. In this work, the self-integrated all-in-one fabric-based supercapacitors (FSCs) with excellent capacitive behavior, flexibility and scalability are designed and fabricated by simply screen-printing the multi-walled carbon nanotubes (MWCNTs) ink on both sides of fabric-based composite separator. The interlocked-like electrode configuration of self-integrated FSC enables electrolyte ions to be transported in transverse and perpendicular directions, and it greatly improved the areal capacitance and reduced internal resistance. Moreover, the assembled FSC exhibits excellent flexibility and stability even under dynamic bending with relatively high strain rates (20% s−1), and 86.1% capacitance is maintained after 1000 bending cycles. Most importantly, the simultaneous series and parallel integration scheme of self-integrated FSCs is realized by versatile screen-printing technique, demonstrating the great potential to simultaneously improve output voltage, overall capacity and potability in a relatively small dimension. Generally, the unique electrode configuration proposes a cost-effective strategy for mass production of flexible energy storage devices.

Polydopamine-assisted dip-and-dry fabrication of highly conductive cotton fabrics using single-wall carbon nanotubes inks for flexible devices

Polydopamine-assisted dip-and-dry fabrication of highly conductive cotton fabrics using single-wall carbon nanotubes inks for flexible devices

Fully printed MWCNT strain sensor over paper substrate for human motion monitoring

Flexible strain sensors have been used in myriad of applications with studies in human physiological monitoring, robotic operation, and human–machine interaction being intensively explored in recent years. Achieving a cost effective, high-performance flexible strain sensor with high sensitivity, and capable of large-scale production have great importance particularly for next generation of wearable electronics. In the present work, the authors have proposed a strain sensor which has been fabricated by simple screen printing of multi walled carbon nanotube ink over paper substrate in a facile and cost-effective manner. A thin sheet of polyethylene terephthalate. was laminated over the sensor surface to ascertain its stability towards environmental effects and physical movements. The characteristics of the printed strain sensor were systematically analyzed for its electrical performance with strain variations, repeatability, dynamic response and durability of the same was also investigated. The strain sensor exhibited a maximum gauge factor of 31.9 within the applied strain of 0%–1.72% and durability of 1000 bending cycles with a response and a recovery time of ∼13 ms and ∼17 ms respectively. Further, the fabricated strain sensors was also attached to various locations around human joints (knee, finger, elbow and wrist) and demonstrated significant sensing performance under different bending strains with superior mechanical robustness suitable for stable human motion monitoring for healthcare application.

Carbon Nanotube Ink Dispersed by Chitin Nanocrystals for Thermoelectric Converter for Self-Powering Multifunctional Wearable Electronics.

The screen-printing process of conductive ink can realize simple and large-scale manufacture of micro/nano patterns for producing wearable electronic products. Herein, chitin nanocrystals (ChNCs) are used as a dispersant for the preparation of multiwalled carbon nanotube (MWCNT) ink with high viscosity and uniformity by ultrasound treatment. ChNCs can interact with MWCNT in noncovalent ways, including π-π and hydrophobic interactions. ChNCs/MWCNT (CCNT) ink does not aggregate even after standing for 3 months with a maximum MWCNT concentration of 33mg mL-1 and dispersion efficiency of 91.1%. Using CCNT ink, a paper-based thermoelectric generator (TEG) is manufactured by screen-printing technology. With good thermoelectric and strain sensing properties, CCNT coated paper can stably collect human energy at room temperature to realize self-powering. The CCNT coated paper-based TEG can convert thermal voltage signals into musical notes, monitor the changes in human behavior and respiratory rate, and monitor joint movements. Moreover, CCNT coated paper has no cytotoxicity by CCK-8 and live/dead staining. This work puts forward a strategy of green preparation of MWCNT-based ink by adding renewable chitin, which opens up a new way to apply MWCNT-based ink in self-powering wearable multifunctional sensors.

Screen printing of graphene-based nanocomposite inks for flexible organic integrated circuits

Graphene and multiwalled carbon nanotube (CNT) composites have been reported to be suitable conductive inks for screen-printing technology, which is a viable option for electrode patterning in organic integrated circuits. Considering the physical properties of the graphene–CNT composite ink, the optimized screen-printing conditions produce graphene–CNT patterns with good pattern fidelity. In addition, the use of a centrifugal mixer enables the composite to disperse graphene and CNT molecules well, stabilizing electrical conductance. In this study, these screen-printed graphene–CNT electrodes were applied to fabricate organic field-effect transistors (OFETs) on a glass substrate. The p- and n-type devices performed satisfactorily. Furthermore, screen printing of graphene–CNT enabled the integration of OFETs for fabricating complementary inverters, NAND, and NOR gates. We believe that the characterization of graphene–CNT inks can promote the advancement of organic integrated circuits beyond unit OFET devices based on an easy-to-use screen-printing technique. • Graphene/CNT composite ink was developed for screen-printing technique. • Using a centrifugal mixer produced well-distributed graphene/CNT patterns with high fidelity. • Integrated circuits with screen-printed graphene/CNT showed robust operation.

Disposable electropolymerized molecularly imprinted electrochemical sensor for determination of breast cancer biomarker CA 15-3 in human serum samples

Initially, a printed electrode was fabricated in a paper substrate using carbon nanotube ink, graphite pencil and silver nanoparticle ink. For that the electrode was modified with gold nanoparticles and a molecularly imprintedpolymer (MIP) using CA 15-3 as target molecule. The Atomic Force Microscopy (AFM) images exhibited the change in the morphology after each electrode modification. The roughness increasedafter the electropolymerization, and decreased after the extraction procedure. Next, slightly increased again associated to the interaction of CA 15-3 and the imprinted sites. Finally, the Fourier Transform Infrared Spectroscopy (FTIR) results suggested the extraction/rebinding of CA 15-3 in the MIP sensor and also indicated that the NIP sample do not have specific cavities for the CA 15-3. In short, under optimized conditions, the CNE/AuNP is incubated with CA 15-3 (40 U mL−1) for 2 h at 4 °C. Then the electropolymerization was carried out in the potential range of −0.2 to 1.0 V during 20 cycles at scan rate of 50 mV s−1 using a solution containing 15 mM of oPD. After electropolymerization, the sensor was washed with oxalic acid solution for 2 h, leading to the formation of imprinted cavities. The rebinding process was subsequently constructed for 1 h at 4 °C using CA 15-3 solution. The reproducibility and interference studies showed that the sensor can be reproducible and specific for CA 15-3. Then the sensor was applied in determination of CA 15-3 in samples of serum and saliva. The use in serum presented good recovery, but the application in saliva was not satisfactory. Therefore, the sensor CNE/AuNP/MIP could be used in the determination of CA 15-3 in serum samples.