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Herein, T4‐bacteriophage‐funcionalizated magnetic Janus micromotors are used for the first time for highly selective Escherichia coli (E. coli) recognition and detection. The micromotors propel at speeds of up to 40 µm s−1 in complex biological samples for on‐the‐fly capture of E. coli "strain B"‐thiolated T4 bacteriophage complex. Detection is achieved by a simplified colorimetric readout in connection with gold nanoparticles. The detection limit meets the cut‐off for the fast diagnosis of urinary tract infections. The bacteriophage‐engineered micromotors are tested on bacteria isolated from urine samples and in serum isolated from negative blood cultures from hospital patients with excellent selectivity and reliability. The new strategy described here holds considerable promise for the multiplexed detection of a myriad of bacteria strains using tailored bacteriophages. Technically, this is the first microplate‐reader integrated micromotor approach, crossing another bridge from the research lab to the practical use of micromotors. Specifically, these results represent a qualitative step forward in the use of micromotor technology with sophisticated functionalization for fast bacteria screening in clinical settings. [ABSTRACT FROM AUTHOR]

Micromotors (MMs) are micro and nanoscale devices capable of converting energy into autonomous motion. Metal–organic frameworks (MOFs) are crystalline materials that display exceptional properties such as high porosity, internal surface areas, and high biocompatibility. As such, MOFs have been used as active materials or building blocks for MMs. In this highlight, we describe the evolution of MOF-based MMs, focusing on the last 3 years. First, we covered the main propulsion mechanisms and designs, from catalytic to fuel-free MOF-based MMs. Secondly, we discuss recent applications of new fuel-free MOFs MM to give a critical overview of the current challenges of this blooming research field. The advantages and challenges discussed provide a useful guide for the design of the next generation MOF MMs toward real-world applications. [ABSTRACT FROM AUTHOR]

Herein, we describe the design of a portable device integrated with micromotors for real-time fluorescence sensing of (bio)markers. The system comprises a universal 3D printed platform to hold a commercial smartphone, which is equipped with an external magnification optical lens (20–400×) and tailor-made emission filters directly attached to the camera, an adjustable sample holder to accommodate a glass slide and laser excitation sources. On a first approach, we illustrate the suitability of the platform using magnetic Janus micromotors modified with fluorescent ZnS@CdxSe1−x quantum dots for real-time ON–OFF mercury detection. On a second approach, graphdiyne tubular catalytic micromotors modified with a rhodamine labelled affinity peptide are used for the OFF–ON detection of cholera toxin B. The micromotor-based smartphone for fluorescence sensing approach was compared to a high-performance optical microscope, and similar analytical features were obtained. This versatility allows for easy integration of micromotor fluorescence sensing strategies based on different propulsion mechanisms, allowing for its future use with a myriad of biomarkers and even multiplexed schemes. [ABSTRACT FROM AUTHOR]

Graphene oxide/PtNPs/Fe2O3"dual‐propelled" catalytic and fuel‐free rotary actuated magnetic Janus micromotors modified with the lanbiotic Nisin are used for highly selective capture/inactivation of gram‐positive bacteria units and biofilms. Specific interaction of Nisin with the Lipid II unit of Staphylococcus Aureus bacteria in connection with the enhanced micromotor movement and generated fluid flow result in a 2‐fold increase of the capture/killing ability (both in bubble and magnetic propulsion modes) as compared with free peptide and static counterparts. The high stability of Nisin along with the high towing force of the micromotors allow for efficient operation in untreated raw media (tap water, juice and serum) and even in blood and in flowing blood in magnetic mode. The high selectivity of the approach is illustrated by the dramatically lower interaction with gram‐negative bacteria (Escherichia Coli). The double‐propulsion (catalytic or fuel‐free magnetic) mode of the micromotors and the high biocompatibility holds considerable promise to design micromotors with tailored lanbiotics that can response to the changes that make the bacteria resistant in a myriad of clinical, environmental remediation or food safety applications. [ABSTRACT FROM AUTHOR]

Graphdiyne (GDY), a new kind of two‐dimensional (2D) material, was combined with micromotor technology for "on‐the‐fly" operations in complex biomedia. Microtubular structures were prepared by template deposition on membrane templates, resulting in functional structures rich in sp and sp2 carbons with highly conjugated π networks. This resulted in a highly increased surface area for a higher loading of anticancer drugs or enhanced quenching ability over other 2D based micromotors, such as graphene oxide (GO) or smooth tubular micromotors. High biocompatibility with almost 100 % cell viability was observed in cytotoxicity assays with moving micromotors in the presence of HeLa cells. On a first example, GDY micromotors loaded with doxorubicin (DOX) were used for pH responsive release and HeLa cancer cells killing. The use of affinity peptide engineered GDY micromotors was also illustrated for highly sensitive and selective fluorescent OFF–ON detection of cholera toxin B through specific recognition of the subunit B region of the target toxin. The new developments illustrated here offer considerable promise for the use of GDY as part of micromotors in living biosystems. [ABSTRACT FROM AUTHOR]

Micromotors are man‐made nano/microscale devices capable of transforming energy into mechanical motion. The accessibility and force offered by micromotors hold great promise to solve complex biomedical challenges. This Review highlights current progress and prospects in the use of nano and micromotors for diagnosis and treatment of infectious diseases and cancer. Motion‐based sensing and fluorescence switching detection strategies along with therapeutic approaches based on direct cell capture; killing by direct contact or specific drug delivery to the affected site, will be comprehensively covered. Future challenges to translate the potential of nano/micromotors into practical applications will be described in the conclusions. [ABSTRACT FROM AUTHOR]

A light‐driven multifunctional Janus micromotor for the removal of bacterial endotoxins and heavy metals is described. The micromotor was assembled by using the biocompatible polymer polycaprolactone for the encapsulation of CdTe or CdSe@ZnS quantum dots (QDs) as photoactive materials and an asymmetric Fe3O4 patch for propulsion. The micromotors can be activated with visible light (470–490 nm) to propel in peroxide or glucose media by a diffusiophoretic mechanism. Efficient propulsion was observed for the first time in complex samples such as human blood serum. These properties were exploited for efficient endotoxin removal using lipopolysaccharides from Escherichia coli O111:B4 as a model toxin. The micromotors were also used for mercury removal by cationic exchange with the CdSe@ZnS core–shell QDs. Cytotoxicity assays in HeLa cell lines demonstrated the high biocompatibility of the micromotors for future detoxification applications. [ABSTRACT FROM AUTHOR]

Propulsion at the microscale has attracted significant research interest. In this work, a numerical simulation to explain the speed boost of up to 34 % experienced by transition metal dichalcogenides (TMD) based micromotors under the effect of applied magnetic fields is described. The simulations show that, when an external magnetic field is applied, the flow regime changes from turbulent to laminar. This causes an increase in the residence time of the fuel over the catalyst surface, which enhances the oxygen production. The more efficient generation and growth of the bubbles lead to an increase of the capillary force exerted by them. Interestingly, the effect is more pronounced as the level of fuel decrease. The validity of the model is also proven by comparing both theoretical and experimental results. Interestingly, the speed enhancement in magnetic mode depends on geometrical factors only, as a similar phenomenon was observed in a variety of microjets with a variable surface roughness. The understanding of such phenomena will open new avenues for understanding and controlling the motion behavior of high‐towing‐force catalytic micromotors. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Surfactant-free β-galactosidase micromotors are explored here as moving biocatalyst for highly efficient lactose hydrolysis from raw milk. The coupling of the hydrolytic properties of such enzyme with the efficient movement of carbon nanotube tubular micromotors results in nearly 100% lactose hydrolysis and two fold removal efficiency as compared with static conditions and with free enzyme. The incorporation of an inner Ni layer allows its reusability to operate in batch mode. The rough micromotor surface area allows the immobilization of a high loading of β-galactosidase and results in an increase in the enzyme affinity toward lactose. The new micromotor concept opens new avenues for the use of micromotors as moving immobilized biocatalyst to improve the technological process not only in food industry but also in other fields. [ABSTRACT FROM AUTHOR]

Magnetic reduced graphene oxide/nickel/platinum nanoparticles (rGO/Ni/PtNPs) micromotors for mycotoxin analysis in food samples were developed for food‐safety diagnosis. While the utilization of self‐propelled micromotors in bioassays has led to a fundamentally new approach, mainly due to the greatly enhanced target–receptor contacts owing to their continuous movement around the sample and the associated mixing effect, herein the magnetic properties of rGO/Ni/PtNPs micromotors for mycotoxin analysis are additionally explored. The micromotor‐based strategy for targeted mycotoxin biosensing focused on the accurate control of micromotor‐based operations: 1) on‐the‐move capture of free aptamers by exploiting the adsorption (outer rGO layer) and catalytic (inner PtNPs layer) properties and 2) micromotor stopped flow in just 2 min by exploiting the magnetic properties (intermediate Ni layer). This strategy allowed fumonisin B1 determination with high sensitivity (limit of detection: 0.70 ng mL−1) and excellent accuracy (error: 0.05 % in certified reference material and quantitative recoveries of 104±4 % in beer) even in the presence of concurrent ochratoxin A (105–108±8 % in wines). These results confirm the developed approach as an innovative and reliable analytical tool for food‐safety monitoring, and confirm the role of micromotors as a new paradigm in analytical chemistry. [ABSTRACT FROM AUTHOR]

Janus particles, named after the two-faced Roman god Janus, are microparticles with different surface structures, which combine one or more chemical properties - or nanomaterials - in a single unit. Regarding the capabilities of Janus particles and micromotors for electrochemical biosensing, Ma et al. illustrated the use of antibody-modified Fe SB 3 sb O SB 4 sb @SiO SB 2 sb /Pt Janus micromotors for immunoglobulin G (IgG) detection. [Extracted from the article]

Magnetocatalytic hybrid Janus micromotors encapsulating phenylboronic acid (PABA) modified graphene quantum dots (GQDs) are described herein as ultrafast sensors for the detection of deadly bacteria endotoxins. A bottom-up approach was adopted to synthesize an oil-in-water emulsion containing the GQDs along with a high loading of platinum and iron oxide nanoparticles on one side of the Janus micromotor body. The two different 'active regions' enable highly efficient propulsion in the presence of hydrogen peroxide or magnetic actuation without the addition of a chemical fuel. Fluorescence quenching was observed upon the interaction of GQDs with the target endotoxin (LPS), whereby the PABA tags acted as highly specific recognition receptors of the LPS core polysaccharide region. Such adaptive hybrid operation and highly specific detection hold considerable promise for diverse clinical, agrofood, and biological applications and integration in future lab-on-chip technology. [ABSTRACT FROM AUTHOR]

Self-propelled micromotors offer considerable promise to solve electroanalytical challenges. This timely review provides a comprehensive overview of the potential of Janus micromotors for new electroanalytical and biosensing applications. We will describe first the use of Janus micromotors to assist electrochemical measurements using strip-based microvolume electrodes. Recent advances on actively moving electrochemical (bio)sensors, ranging from enzyme-powered to light-emitting electrochemically powered Janus micromotors, will be also described. We hope that this Review provides the reader with some general knowledge and future prospect of the potential of Janus micromotors for electroanalysis. [ABSTRACT FROM AUTHOR]

This frontier review covers recent advances in the field of nanomaterial-based micromotors for the development of novel labs-on-a-chip (LOCs). In this review, we will discuss how carbon nanomaterials “on-board” of micromotors offer particular promise for diverse LOC applications. New trends in the field, directed towards the use of quantum dots and nanoparticles as functional materials for sophisticated micromotors, will be reviewed. Micromotor strategies using functionalized catalytic microengines to capture and transport (bio)molecules between the different reservoirs of LOC devices will also be covered. These recent advances are bringing closer our hopes for personalized medicine and food safety assurance, among others. [ABSTRACT FROM AUTHOR]

A new “on-the-fly” chemical optical detection strategy based on the incorporation of fluorescence CdTe quantum dots (QDs) on the surface of self-propelled tubular micromotors is presented. The motion-accelerated binding of trace Hg to the QDs selectively quenches the fluorescence emission and leads to an effective discrimination between different mercury species and other co-existing ions. [ABSTRACT FROM AUTHOR]

Oxidative Dekontaminierung: Eine effektive Strategie zur oxidativen Neutralisierung von Organophosphor ‐ Nervengiften basiert auf Mikromotoren mit Eigenantrieb. Die Bewegung vieler Motoren durch eine Peroxid ‐ aktivierte kontaminierte Lösung verbessert die Dekontaminierungseffizienz im Vergleich zu gewöhnliche Neutralisierungsprozessen von chemischen Kampfstoffen. [ABSTRACT FROM AUTHOR]

Janus Microswimmers: Oscillatory Light-Emitting Biopolymer Based Janus Microswimmers (Adv. Keywords: biopolymer; chemiluminescence; hydrogels; Janus micromotors; propulsion; Prussian Blue EN biopolymer chemiluminescence hydrogels Janus micromotors propulsion Prussian Blue 1 1 1 05/23/20 20200520 NES 200520 An alginate based Janus particle, depicted as a floating sphere, contains Prussian blue as a bifunctional catalyst, decomposing hydrogen peroxide into oxygen bubbles, and catalyzing simultaneously the chemiluminescent reaction of luminol. Biopolymer, chemiluminescence, hydrogels, Janus micromotors, propulsion, Prussian Blue. [Extracted from the article]

Keywords: bacteria; cancer cell; killing; micromotor; therapy This Review highlights current progress and prospects in the use of nano and micromotors for diagnosis and treatment of infectious diseases and cancer. [Extracted from the article]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The multi‐light‐controlled propulsion and on‐the‐fly chemical acceleration capabilities of micromotors based on Pt, Pd, and MnO2 catalysts is described by A. Escarpa, B. Jurado, R. M. Hormigos in their Communication on page 3128 ff. The built‐in accelerating optical system allows for velocity control over the entire UV/Vis light spectrum for future on‐demand operation, motion‐based sensing, and beyond. [ABSTRACT FROM AUTHOR]

Food poisoning caused by bacteria is a major cause of disease and death worldwide. Herein we describe the use of Janus micromotors as mobile sensors for the detection of toxins released by enterobacteria as indicators of food contamination. The micromotors are prepared by a Pickering emulsion approach and rely on the simultaneous encapsulation of platinum nanoparticles for enhanced bubble-propulsion and receptor-functionalized quantum dots (QDs) for selective binding with the 3-deoxy-D-manno-oct-2-ulosonic acid target in the endotoxin molecule. Lipopolysaccharides (LPS) from Salmonella enterica were used as target endotoxins, which upon interaction with the QDs induce a rapid quenching of the native fluorescence of the micromotors in a concentration-dependent manner. The micromotor assay can readily detect concentrations as low as 0.07 ng mL-1 of endotoxin, which is far below the level considered toxic to humans (275 μg mL-1). Micromotors have been successfully applied for the detection of Salmonella toxin in food samples in 15 min compared with several hours required by the existing Gold Standard method. Such ultrafast and reliable approach holds considerable promise for food contamination screening while awaiting the results of bacterial cultures in a myriad of food safety and security defense applications. [ABSTRACT FROM AUTHOR]

A novel Janus micromotor-based strategy for the direct determination of diphenyl phthalate (DPP) in food and biological samples is presented. Mg/Au Janus micromotors are employed as novel analytical platforms for the degradation of the non-electroactive DPP into phenol, which is directly measured by difference pulse voltammetry on disposable screen-printed electrodes. The self-movement of the micromotors along the samples result in the generation of hydrogen microbubbles and hydroxyl ions for DPP degradation. The increased fluid transport improves dramatically the analytical signal, increasing the sensitivity while lowering the detection potential. The method has been successfully applied to the direct analysis of DPP in selected food and biological samples, without any sample treatment and avoiding any potential contamination from laboratory equipment. The developed approach is fast (~5 min) and accurate with recoveries of ~100%. In addition, efficient propulsion of multiple Mg/Au micromotors in complex samples has also been demonstrated. The advantages of the micromotors-assisted technology, i.e., disposability, portability, and the possibility to carry out multiple analysis simultaneously, hold considerable promise for its application in food and biological control in analytical applications with high significance. [ABSTRACT FROM AUTHOR]

Tacrolimus (FK506) is a macrolide lactone immunosuppressive drug that is commonly used in transplanted patients to avoid organ rejection. FK506 exhibits high inter- and intra-patient pharmacokinetic variability, making monitoring necessary for organ graft survival. This work describes the development of a novel bioassay for monitoring FK506. The bioassay is based on using polycaprolactone-based (PCL) magnetic Janus micromotors and a recombinant chimera receptor that incorporates the immunophilin tacrolimus binding protein 1A (FKBP1A) tagged with Emerald Green Fluorescent Protein (EmGFP). The approach relies on a fluorescence competitive bioassay between the drug and the micromotors decorated with a carboxylated FK506 toward the specific site of the fluorescent immunophilin. The proposed homogeneous assay could be performed in a single step without washing steps to separate the unbound receptor. The proposed approach fits the therapeutic requirements, showing a limit of detection of 0.8 ng/mL and a wide dynamic range of up to 90 ng/mL. Assay selectivity was evaluated by measuring the competitive inhibition curves with other immunosuppressive drugs usually co-administered with FK506. The magnetic propulsion mechanism allows for efficient operation in raw samples without damaging the biological binding receptor (FKBP1A-EmGFP). The enhanced target recognition and micromixing strategies hold considerable potential for FK506 monitoring in practical clinical use. [ABSTRACT FROM AUTHOR]

A high-performance graphene-based micromotor strategy for simultaneous, fast, and reliable assessment of two highly concerning mycotoxins (fumonisin B1 (FB1) and ocratoxin A (OTA)) has successfully been developed. The assay principle is based on the selective recognition from aptamers to the target mycotoxins and further "on-the-move" fluorescence quenching of the free aptamer in the outer layer of unmodified reduced graphene (rGO; sensing layer) micromotors. Template-prepared rGO/platinum nanoparticles (PtNPs) tubular micromotors were synthesized rapidly and inexpensively by the direct electrodeposition within the conical pores of a polycarbonate template membrane. The new wash-free approach offers using just 1 µL of sample, a simultaneous and rapid "on-the-fly" detection (2 min) with high sensitivity (limits of detection of 7 and 0.4 ng/mL for OTA and FB1, respectively), and high selectivity. Remarkable accuracy (Er < 5%) during the mycotoxin determination in certified reference material as well as excellent quantitative recoveries (96-98%) during the analysis of food samples were also obtained. The excellent results obtained allow envisioning an exciting future for the development of novel applications of catalytic micromotors in unexplored fields such as food safety diagnosis. [ABSTRACT FROM AUTHOR]

A fast and reliable OFF-ON micromotors (MM)-based aptassay for rapid, sensitive, and accurate determination of procalcitonin (PCT) as one of the leading neonatal sepsis biomarkers in very low birth weight infants' serum samples is proposed. MM were composed of three specific functional layers: graphene oxide (GO) as sensing layer, Ni for magnetic guidance and platinum nanoparticles (PtNPs) as catalytic layer for self-propulsion (MM GO/Ni/PtNPs). The OFF-ON strategy relies on the binding of the aptamer tagged with alexa-405 as fluorescent label (Apt PCT , λ em =447 nm) onto the GO outer layer of the MM (GO MM) to induce its fluorescence quenching (GO MM -Apt PCT , OFF state); which is next recovered due to selectively binding of the aptamer to the PCT and their separation from the GO MM surface (PCT-Apt PCT , ON state). The fast OFF-ON on-the-fly aptassay allowed in just 5 min a highly selective and sensitive (LOD = 0.01 ng mL−1) PCT determination in clinical samples from very low birth weight infants with sepsis suspicion, using only 25 µL of sample in a clinically relevant range of concentrations (0.03–1280 ng mL−1). The high concordance between the PCT levels obtained by our MM GO/Ni/PtNPs -based aptassay and those obtained by the Hospital, demonstrated the analytical potency of our approach for the analysis of neonatal samples as well as its potential to be used as a pre-diagnostic tool for sepsis. [Display omitted] • A micromotors-based aptassay for neonatal sepsis diagnosis was developed. • On-the-fly aptassay working on low volume clinical samples from neonates. • OFF-ON aptassay for a fast, sensitive, and accurate procalcitonin determination. • The aptassay was validated by analyzing serum from very low birth weight infants. • Micromotors become a powerful analytical tool for neonatal sepsis diagnosis. [ABSTRACT FROM AUTHOR]

Carbon allotropes nanomaterials are explored here for the preparation of highly efficient tubular micromotors: 0D (C60 fullerene), 1D (carbon nanotubes), 2D (graphene), and 3D (carbon black, CB). The micromotors are prepared by direct electrochemical reduction or deposition of the nanomaterial into the pores of a membrane template. Subsequent electrodeposition of diverse inner catalytic layers (Pt, Pd, Ag, Au, or MnO2) allows for efficient bubble-propulsion in different media (seawater, human serum, and juice samples). Atomic-force microscopy (AFM) and scanning electron microscopy characterization reveals that the micromotors exhibit a highly rough outer surface and highly microporous inner catalytic structures. A key aspect derived from the AFM characterization is the demonstration that the rough outer surface of the micromotors can greatly affect their overall speed. To date, the literature has only focused on studying the effect of the inner catalytic layer upon their speed and performance and has underestimated the effect of the outer surface layer. The speed of carbon-based micromotors is a compromise between two opposite forces: the increased catalytic activity because of improved fuel decomposition in the inner catalytic layer, which propels their advance, and the friction of the rough outer surface with the fluid, which is opposed to it. The largest outer surface area associated with the highest surface roughness of C60 fullerene and carbon black-Pt micromotors leads to a large friction force, which results in a reduced speed of -180 μm/s (1% H2O2). In contrast, for carbon-nanotube-Pt based micromotors, the dominant force is the high catalytic activity of the micromotor, which allows them to reach ultrafast speeds up to 440 μm/s (1% H2O2). The new protocol opens new avenues for the universal preparation of carbon based multifunctional micromotors for a myriad of practical applications exploiting the features of carbon allotropes. [ABSTRACT FROM AUTHOR]

Herein we describe an "OFF-ON" Janus micromotor approach for the fast (5 min) and sensitive determination (limit of detection, 120 pM) of Escherichia coli O111:B4 lipopolysaccharide (LPS) associated with sepsis shock in microliter samples. The OFF-ON strategy relies on the loading of a specifically designed rhodamine-labeled affinity peptide into WS 2 –Pt–Fe 2 O 3 polycaprolactone Janus micromotors. Specific attachment of the peptide with the WS 2 via electrostatic and hydrophobic interactions results in fluorescent quenching, which is subsequently recovered by the detachment of the probe in the presence of the target LPS. Peptide loading into the micromotor structure increases the overall stability for over 2 months without any change in its properties and excellent analytical performance. No fluorescence recovery is observed in the presence of LPS with a similar structure, illustrating the high selectivity of the protocol, along with quantitative recoveries in human serum and bacteria cultures. The method was validated against the gold standard Limulus Amoebocyte lysate assay in real bacteria culture containing naturally occurring LPS, with similar recoveries in both cases. The micromotors hold great potential to carry out analytical measurements in real-time with small amounts of sample and reagents, allowing for fast detection of deadly toxins with high clinical relevance. • "OFF-ON" Janus micromotors for endotoxin detection. • First time WS 2 is encapsulated in micromotors as "active" quenching material. • Dual micromotors role as "probe storage units" for long stability and as "on-the-fly" sensors. • Nanomolar detection of endotoxin is achieved with extremely reduced analysis time. [ABSTRACT FROM AUTHOR]

Based on the exceptional and new opened biosensing possibilities of self-propelled micromotors, a micromotor-based immunoassay (MIm) has smartly been designed for C-reactive protein (CRP) determination in plasma of preterm infants with sepsis suspicion. The design of the micromotors involved the electrosynthesis of a carbon-based outer layer (for antibody functionalization), an intermediate Ni layer (for magnetic guidance and stopped flow operations) and PtNPs inner catalytic layer (for catalytic bubble propulsion). Micromotors biofunctionalization on the outer layer (using carbon black (CB), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), and biocompatible propulsion capabilities, were carefully studied. Magnetic rGO/Ni/PtNPs micromotors exhibited the most efficient and reproducible (CV = 9%) anti-CRP functionalization, controlled stopped-flow operations as well as efficient bubble propulsion (1% H 2 O 2 , 1,5% NaCh, speed 140 μm s-1). Analytical performance of MIm was excellent, allowing the direct (without dilution), sensitive (LOD = 0.80 μg/mL), and accurate CRP determination (E r = 1%) in hardly available preterm babies' plasma samples with suspected sepsis using very low volumes (<10 μL) and in just 5 min of on-the-fly bioassay. Overall, the results obtained allowed the fast and reliable sepsis diagnostics in preterm babies' individuals with suspected sepsis, not only proving the usefulness of the approach as its potential utilization as point-of-care device for clinical analysis but drawing new horizons in extremely low sample volumes-based diagnostics. • On-the-fly C-reactive protein immunoassay for early neonatal sepsis diagnosis. • Magnetic micromotors-based immunosensing strategy for fast and accurate C-reactive protein determination. • Antibody-functionalization of carbon-based micromotors: smart swimming in very low plasma sample volumes. • Faster micromotors in propulsion media: designing fuel and surfactant composition. [ABSTRACT FROM AUTHOR]