Laser writing is used to structure surfaces in many different ways in materials and life sciences. However, combinatorial patterning applications are still limited. Here we present a method for cost-efficient combinatorial synthesis of very-high-density peptide arrays with natural and synthetic monomers. A laser automatically transfers nanometre-thin solid material spots from different donor slides to an acceptor. Each donor bears a thin polymer film, embedding one type of monomer. Coupling occurs in a separate heating step, where the matrix becomes viscous and building blocks diffuse and couple to the acceptor surface. Furthermore, we can consecutively deposit two material layers of activation reagents and amino acids. Subsequent heat-induced mixing facilitates an in situ activation and coupling of the monomers. This allows us to incorporate building blocks with click chemistry compatibility or a large variety of commercially available non-activated, for example, posttranslationally modified building blocks into the array's peptides with >17,000 spots per cm2.

Vaccinations are among the most potent tools to fight infectious diseases. However, cross-reactions are an ongoing problem and there is an urgent need to fully understand the mechanisms of the immune response. For the development of a methodological workflow, the linear epitopes in the immune response to the tetanus toxin is investigated in sera of 19 vaccinated Europeans applying epitope mapping with peptide arrays. The most prominent epitope, appearing in nine different sera ( IHLVNNESSEVIVHK ), is investigated in a substitution analysis to identify the amino acids that are crucial for the binding of the corresponding antibody species - the antibody fingerprint. The antibody fingerprints of different individuals are compared and found to be strongly conserved ( ExxEVIVxK ), which is astonishing considering the randomness of their development. Additionally, the corresponding antibody species is isolated from one serum with batch chromatography using the amino acid sequence of the identified epitope and the tetanus specificity of the isolated antibody is verified by ELISA. Studying antibody fingerprints with peptide arrays should be transferable to any kind of humoral immune response toward protein antigens. Furthermore, antibody fingerprints have shown to be highly disease-specific and, therefore, can be employed as reliable biomarkers enabling the study of cross-reacting antigens.

In this review, we describe different methods of microarray fabrication based on the use of micro-particles/-beads and point out future tendencies in the development of particle-based arrays. First, we consider oligonucleotide bead arrays, where each bead is a carrier of one specific sequence of oligonucleotides. This bead-based array approach, appearing in the late 1990s, enabled high-throughput oligonucleotide analysis and had a large impact on genome research. Furthermore, we consider particle-based peptide array fabrication using combinatorial chemistry. In this approach, particles can directly participate in both the synthesis and the transfer of synthesized combinatorial molecules to a substrate. Subsequently, we describe in more detail the synthesis of peptide arrays with amino acid polymer particles, which imbed the amino acids inside their polymer matrix. By heating these particles, the polymer matrix is transformed into a highly viscous gel, and thereby, imbedded monomers are allowed to participate in the coupling reaction. Finally, we focus on combinatorial laser fusing of particles for the synthesis of high-density peptide arrays. This method combines the advantages of particles and combinatorial lithographic approaches.

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This study discusses the results of a Recurrence quantification analysis (RQA) of the Rössler system with a fractional order ($$q_1$$ q 1 ) of the derivative in the first equation. The fractional order $$q_1$$ q 1 changes slightly in the range $$q_1 \in \langle 0.9,1.0\rangle$$ q 1 ∈ ⟨ 0.9 , 1.0 ⟩ . Even with such relatively small changes in the $$q_1$$ q 1 derivative, significant changes in the dynamics of the system are observed between the bifurcation diagrams determined for the bifurcation parameter a. Nevertheless, as $$q_1$$ q 1 decreases one can notice the preservation of some structures of the bifurcation diagram, in particular the main periodic windows of the integer-order Rössler system. The RQA shows clear differences between various regular windows of the integer system and only slight changes in these windows are caused by an increase in the system’s fractionality. Nonetheless, by selecting appropriate recurrence variables it is possible to expose the changes occurring in the regular windows under the influence of the fractionality of the system. This approach allows for the detection of the fractional character of the system through a recurrence analysis of the time series taken from periodic regions.